- For the episode, see "".
- For her human personality, see Samantha Arias.
- "I am from the time before fathoming. Born to cleanse the scourge and deliver the awakening. I am Reign."
- —Reign to Supergirl[src]
Creation and sent to Earth
Reign was created by the Children of Juru, an ancient, secret coven on Krypton dedicated to the old polytheistic beliefs of Yuda Kal. The leader of the Worldkillers designed after centuries of research, Reign was imbued into a genetically engineered Kryptonian using the Harun-El, a mystical black rock which possessed dark magic that augmented her capabilities beyond even those of her race when exposed to a yellow sun. Due to being created with the Harun-El, Reign honed her powers in Juru, an alternate dimension where the Worldkiller personas resided when dormant. As part of an ancient "End of Worlds" prophecy, Reign and her sisters, Purity and Pestilence, were designed "execute justice" by purifying Krypton of sin and burning it to the ground, which would make way for the Juru people's order to prosper.
However, the Children of Juru's plans were derailed due to the planet's impending destruction. On the day of Krypton's devastation in 1979, a group of hooded coven members placed Reign in an escape pod, feeding the newly-created infant a drop of blood to sustain her. She was sent to Earth, where the coven intended for her to grow strong and reign. Purity and Pestilence were sent along with Reign and would awaken once she was ready.
Reign's pod landed on Earth around 1989 (presumably remaining in stasis for 10 years prior). She was taken in by Patricia Arias, and her human half became known as Samantha Arias. Despite remaining dormant within Samantha for years, Reign would partially manifest as she grew stronger. For example in 1999, she began influencing Samantha to repeatedly draw the Worldkillers' symbol in a trance. Reign was to fully manifest once her human host came of age. However, in 2005, Samantha became pregnant and gave birth to a daughter, Ruby Arias. This biological process ended up delaying the Dark Kryptonian's awakening.
12 years later in late 2017, Reign was unexpectedly triggered when Samantha used super strength to save Ruby's life. Reign's powers began to emerge, cumulating in her transforming into a hideous monster in Juru. The transformation was presented to Samantha as a "nightmare", a warning of the Worldkillers' "End of Days" prophecy coming into fruition.
As the weeks passed, Reign's powers began to grow stronger, affecting Samantha and soon rendering her skin invulnerable.
Upon discovering her powers, Samantha was prompted to seek out the truth of her past from Patricia. Patricia showed her Reign's pod, from which Samantha uncovered a crystal. In a remote desert, the crystal uncovered the Fortress of Sanctuary, a piece of Krypton which would house and advise the Worldkillers. The fortress' hologram of Selena, the leader of the Children of Juru, preached that it was time for Reign to emerge. Despite Samantha's resistance, Reign began to completely manifest in her host, painfully repressing Samantha's human self. Her eyes glowing red, Reign eerily stated, "I have awoken" in ancient Kryptonese.
The rise of Reign
Upon the behest of the hologram, Reign aimed to prepare Earth for the "End of Days" prophecy and returned to National City to make her mark. Using her heat vision, she burned the Children of Juru's symbol all over the city throughout the night, completing the first step, the "Mark of the Beast".
A couple of nights later, Samantha saw a news report from L-Corp about a street gang known as the One-Seven Gang causing yet another fatal shooting. Reign was angered by this and began to emerge, but Ruby's arrival at the office brought Sam back to the surface. After Ruby left, Reign took control and flew to the National City Port, where she caught the One-Seven Gang participating in a drug deal. Reign attacked the gang, swiftly and brutally ripping its members to death with her heat vision as punishment for their criminal actions.
Later that night at CatCo Worldwide Media, Samantha learned of Morgan Edge's assassination attempt on her friend and boss, Lena Luthor. She angrily gazed at a picture of Edge and with Reign awakening, coldly stated that he should be dead. Reign exited, ripping open her buttoned blouse to reveal her suit with the Children of Juru's sigil upon her chest. Reign attacked Edge Global during a Christmas Party that night, inciting havoc in the building. She made her way to Edge's office, but he concealed himself in a lead-lined panic room. Unable to spot him through the material, Reign wordlessly left by flying out the window.
Supergirl, intending to draw this new and mysterious Kryptonian out, left her symbol of the House of El on the roof of CatCo. Sensing the challenge, Reign arrived on the roof and waited for the superheroine to arrive. Once Supergirl and Reign met face to face, the former wondered if her opponent was the Devil. Reign negated this, introducing herself as a dispenser of justice on Earth. The Worldkiller revealed she too is from Krypton, having been sent away right before the planet's collapse. Supergirl condemned Reign's terrorizing of the city, to which the Worldkiller protested that the world had been broken down by sin and she will ensure that judgment was dealt to those who eluded it. Supergirl refused to allow her crusade and demanded that the Dark Kryptonian surrender, or else. Amused by her opponent's hubris, Reign compared Supergirl to the residents of Krypton, who worshipped "false gods" while fearing and shunning her creators. Reign claimed the modern Kryptonians let their planet suffocate and burn, threatening to send Supergirl to Purgatory with them if the superheroine tried to get in her way. When Supergirl refused, Reign decided to dispense her justice on her and the two engaged in a fierce duel.
Reign and Supergirl's battle raged throughout National City, leaving a trail of destruction, with the two superbeings evenly matched at first. They soon crashed onto the streets, dueling in front of hundreds of civilians. Reign eventually managed to knock Supergirl down with a punch to the face. As Supergirl became distracted by some nearby onlookers, Reign struck her head with a slab of concrete, drawing blood from the Girl of Steel. As the disbelieved and slightly concussed Supergirl attempted to continue fighting, Reign quickly incapacitated her with a head-butt. Supergirl gathered enough strength to disarm Reign of the concrete and use it to push her away, but the Worldkiller quickly flew back into proximity and hurled a flaming car door at Supergirl before using her heat vision to burn off the Girl of Steel's crest and force the latter onto a roof. Picking up Supergirl by her suit and musing that her weakened and beaten down opponent wasn't a God, the Worldkiller proclaimed she wasn't the Devil, but an entity of truth, justice, and death who would reign. She then dropped Supergirl from the roof, watching as the Girl of Steel fell to the ground and seemingly died. After her triumph, Reign presumably returned to Samantha's home.
Against a Legion
Two days later, Reign took over Samantha upon seeing a newspaper reporting her defeat of Supergirl. She returned to the Fortress of Sanctuary, where Selena's hologram congratulated the Worldkiller on her victory over Supergirl and making her mark. Reign was quickly informed that was still much for her left to do in preparation for the awakening that she is meant to enact. The hologram ordered her to exact deliverance on Earth and target not just sinners, but those who allowed sins to happen through their inaction. Reign then murdered a thief who stole a van and broke into CatCo, where she dropped off the man's body. Reign ordered one of the nearby cameramen to aim his device at her and, despite Lena's protests, began broadcasting her message. Reign accused the people of National City of allowing criminality to roam free in city, as well as being apathetic towards the plague. The Worldkiller declared that she is "here to help" and vowed to show no mercy against such people before flying away.
True to her word, Reign began to target criminality in all its forms, as well as the city's justice system if she deemed they didn't punish criminals enough; she took down a meth lab and then the police when they arrived to stop her.
Later, Reign descended on what appeared to be a bank robbery, preparing to kill the perpetrators. However, the "robbers" and some "hostages" were revealed to be agents from the D.E.O., having set up the operation to lure out the Dark Kryptonian. Initiating the Sundown Protocol against the Worldkiller, the agents attacked Reign with a red sun grenade and sonic weapons, disorienting her. Two agents then pinned her down with a heavy metal wire while Alex Danvers placed a chain of Kryptonite soil around her neck. Reign was initially weakened and in pain, but overcame the Kryptonite's effects and broke her restraints. She used the metal wire to snap Alex's tibia in half, knocking her down. Furiously casting the Kryptonite aside, Reign attempted to kill Alex, only for J'onn J'onzz to intervene and punch her aside. Reign then escaped through a window.
In retaliation for the ambush, Reign invaded Albatross Bay and went on a rampage, striking down convicts and guards alike. She eventually came upon a holding cell and found Thomas Coville praying to a Juru glyph, submitting to her will. Intrigued, Reign wondered how Coville knew those words, to which he preached to be "awoken to them". Reign suspiciously asked if Coville believed claiming salvation would result in her sparing him but Coville revealed he in fact wished to be of service to the Worldkiller's cause. Just then, Reign heard Bon Jovi's "Livin' on a Prayer" blaring outside and left to investigate. Busting through the prison wall, she was faced with a large spaceship rising out of the water with Mon-El and Imra Ardeen preparing to duel her.
Reign warned them not to interfere, as she wanted to purge the world of sin. Imra rhetorically asked why she doesn't start with herself, to which the Worldkiller retorted that she's "not of this world". She flew to the spaceship but the two Legion members to followed her. The ship attempted to shoot Reign down, but she ended up redirecting one of their missiles back to the cannons, destroying them. Imra telepathically threw some weights at Reign while Mon-El rushed at her with a Kryptonite syringe. However, Reign destroyed the weights with her heat vision and used her freeze breath on Mon-El, though Imra saved him with a telepathic bubble. J'onn then ambushed Reign, phasing the both of them underground. After a brief battle, the two flew back above ground, both injured, with their match having ended in a stalemate. When Imra tried to free Mon-El, Reign knocked her aside and prepared to kill Imra for protecting a "sinner". Just then, Supergirl arrived, much to Reign's shock, having believed the Girl of Steel to be dead by her hand. Supergirl attacked the Worldkiller and they both tumbled onto the ground. Reign tried to finish off the superheroine, only for Supergirl to plunge a syringe of concentrated Kryptonite into her neck. Stumbling and gasping in pain, Reign quickly fled.
Reign managed to make her way back to the Fortress of Sanctuary. Writhing in agony until the Kryptonite was flushed out of her bloodstream, Reign soon recovered and was questioned by Selena's hologram as to what happened. The Worldkiller admitted Supergirl gained an edge on her due to unexpected allies. The hologram then revealed to Reign the existence of other Worldkillers, whom she could find on Earth now that she had proven herself. Coville then arrived at the Fortress of Sanctuary, offering to help Reign complete her path.
Searching for her sisters
A week later, the Fortress of Sanctuary sent out Kryptonian phrases that only Reign alone could hear, causing her to emerge and fly there. When Selena's hologram wondered why she arrived late, the Worldkiller expressed that her human side is stronger than she expected; Samantha's increasing resistance, while subconscious for now, made it increasingly difficult for Reign to take and maintain control. The hologram scolded that Sam shouldn't be a hindrance and informed her that the Fortress had detected a signal coming from Fort Rozz. The hologram explained that Supergirl and her allies were headed to the prison, most likely to find Jindah Kol Rozz, the dark high priestess of the Children of Juru who had been imprisoned long before Krypton's destruction. Realizing that Supergirl gaining any of Jindah's knowledge of the Worldkillers' agenda would pose a threat to their plans, Reign boarded her pod to Fort Rozz, intending to find the priestess first.
At Fort Rozz's Dendara Corridor Reign, Reign witnessed Jindah revealing to Supergirl the existence of Purity and Pestilence, the other Worldkillers who would unite under their leader, before announcing her presence and greeting the priestess. Jindah expressed delight to see Reign, believing the two will unite to bring hellfire upon their enemies and restore the Juru's way of life. However, Reign instead deemed Jindah to be a liability and fired her heat vision through the priestess' heart, killing her. Supergirl was shocked that Reign's powers weren't dampened by the blue star Fort Rozz was orbiting, to which Worldkiller gloated that the sun isn't the source of her strength.
Reign mocked that Supergirl was vulnerable whilst de-powered but the superheroine nonetheless tried to reason with Reign; she expressed her belief that a part of the Dark Kryptonian regrets the pain and terror she is causing in her mission (unknowingly reaching out to Samantha), insisting they could deliver justice the right way without being at odds with one another. Reign disagreed and prepared to kill her, only to be attacked by Supergirl's ally, Leslie Willis/Livewire. Livewire battled the Worldkiller, with Reign unable to get a direct hit on the meta-human at first due to her electricity-phasing powers. Once Livewire manifested, Reign derided her as a "nuisance" and fired her heat vision, which the former countered with her electricity. The two powers were evenly matched until Reign got close enough to begin choking Livewire. Supergirl tried to intervene, but was knocked aside. A furious Livewire ordered Reign to leave her friends alone before summoning enough electricity to push each of them back.
Though winded from the encounter, Reign recovered in seconds and descended on an incapacitated Livewire, enraged. Supergirl pleaded her to spare Livewire and offered herself instead. Reign agreed and fired her heat vision at Supergirl, only for Livewire to take the hit, mortally wounding her. Just then, Gayle Marsh/Psi, another one of Supergirl's allies, confronted Reign. As the Worldkiller studied her foe, Psi unleashed a psychic attack on Reign to tap into her deepest fears. Reign immediately began crying out in pain and distress, with Psi's crippling energy overriding her powers and forcing Samantha to the surface by exposing her worst fear - Ruby being taken away from her forever. Once Samantha recovered from the ordeal, she was scared and confused about her current situation but before Supergirl and her allies could help her, Reign took back control of her human host and fled from Fort Rozz, returning to Earth.
Several weeks later, Reign was summoned to the Fortress, where the hologram revealed that one of her sisters, Purity, is beginning to awaken due to the latter's crystal activating but had already been discovered by their adversaries. The hologram urged Reign to retrieve her sister, who needed be brought to the Fortress for their guidance to ensure the Worldkillers' success. Reign agreed and set out to search for Purity.
Reign eventually tracked Purity to the subway, where she met her sister's human half, Julia Freeman. With Supergirl and Mon-El incapacitated earlier by Purity and J'onn occupied with holding up the collapsing structure, Reign immediately moved in. Alex fired her alien gun at the Worldkiller, but Reign quickly disarmed and knocked her down before beginning to crush Alex's ribs with her foot. However, Julia freely gave Reign the opportunity to take her in exchange for sparing Alex. Sensing Purity within her, Reign agreed. Now one step closer to their plan, Reign mused how the Worldkillers would ascend once united. Before the heroes could intervene, Reign abducted Julia and brought her to the Fortress.
Later that night at L-Corp, Samantha's increasing worry and stress with how her latest blackout nearly put Ruby in harm's way, combined with anger when she believed Lena revealed the former's episodes to her daughter, began to trigger the Worldkiller. Amidst Lena's attempts to talk to Sam, Reign emerged and menacingly yelled "Silence!" before threateningly advancing on her. However, when Lena called out her friend's name, Sam immediately woke up from her trance and suppressed Reign.
Battling her human half
A few days later, Lena deliberately angered Samantha to awaken Reign, needing proof of the Worldkiller's existence. Reign tried in vain to escape from the laboratory before Lena suppressed her with a dose of synthesized Kryptonite, though not before obtaining a sample of the former's DNA.
In an effort to isolate and override the enzyme which triggered Reign's manifestation, Lena used electric shocks to stimulate Samantha's pain receptors in order to gain access to the Worldkiller's genome while still suppressing her subconsciousness. As Reign awakened, she met her human self in person for the first time in Juru and cryptically warned Samantha that the Worldkillers were coming for them. Just then, Samantha awakened and took back control.
Not long after, Reign encountered Samantha again in Juru. Admitting her human half was stronger than she thought, the Dark Kryptonian vowed to change that, vengeful about being locked in Juru alone for so long. Reign tried to tempt Samantha into giving into the darkness, promising it was a way to escape the isolated existence she had been "trapped" in since her daughter, Ruby, was born for one of power and control. Reign offered Sam the opportunity to unite into one being, but was refused and suppressed once more.
Reign confronted Samantha in Juru one last time, reiterating her offer. However, Sam rebuffed her again, determined to ensure the Worldkiller would never escape the dark valley. Angered at the rejection, the Dark Kryptonian grabbed Sam by the throat and began choking her, deciding to force her human half to submit instead. Reign vowed to completely annihilate Sam's home and burn it to ash, sadistically promising to personally "cut [Ruby] inside out", taking away her human half's source of strength. Sam resisted and eventually awoke.
As Reign sensed the impending arrival of Purity and Pestilence, she became strong enough to begin dominating over Samantha, forcing her alternate self into Juru. When Supergirl, J'onn, Mon-El, and Imra arrived to warn Lena, the Girl of Steel was shocked to see Reign, recognizing her civilian identity. Reign stated her sisters were coming before Lena gave her another dose of Kryptonite. Just then, Purity and Pestilence arrived and destroyed the laboratory protocols, releasing Reign. Elated to finally join her sisters, Reign transformed into her costume and chanted "El mayarah". The Worldkiller trinity unleashed a powerful wave of crippling energy onto the heroes before escaping.
After being exposed to an ancient Kryptonian rock, mixed with her blood sample by Lena Luthor, Reign separated from Sam and became her own person while still connected to Sam's life force.
She was killed by Sam, who put the water from the Fountain of Lillith into to her mouth, causing wraiths to surround Reign and fly her into the Fountain of Lillith.
- "You have a code. A purpose. You fight against evil and you dispense justice. You're here to make a better world. One without sin in it. But this girl has not sinned. You can't kill her. You won't."
- —Supergirl and Reign [src]
Due to her forced mental programming operating on her as Reign, Sam becomes an exaggerated polar opposite of everything she is, while her world killer persona remains inactive in her default state, for the periods and durations wherein Reign remains in control: a brutal vigilante who indiscriminately kills anyone she sees as an evildoer in order to further her goal of ruling the world, and will react expediently cold and silently murderous whenever she comes across the said people or catch knowledge of such. She is cruel, sadistic and ruthless towards anyone who stands in her way. She is also egotistical; even though she doesn't actually see herself as a "god" or a "devil", she sees herself as "truth", "judgment", "death" and an executor of justice. Thus, her eventual dominion is inevitable and this causes her to also view those who say or stand otherwise as obstructing targets to her goal.
She believes all of her actions are intended to spread justice to all those who deserve it and is not above mocking or taunting those who oppose her whenever Reign has them at her mercy, making it possible to catch her off-guard when she least expects it. She also perceives that humanity has ruined their world and they must all be judged by her without exception. Despite her ruthlessness, she is not above offering prey whom she sees as her equal a chance to stand down, like how she offered Supergirl to do so (threatening to subject the latter "into purgatory" if she chooses to stand in Reign’s way) and was perhaps a hint disappointed when the latter refuses and even responded defiantly, making the disguised (and mentally-overridden) Samantha realize that she had to manhandle her fellow Kryptonian for her insolence.
But despite all of her negative drives and overzealous conviction, it would seem that Sam — as Reign — still retains vestiges of her civilian persona in that she has been known to simply leave be or tolerate those whom she is familiar with as Sam, even if they directly oppose her; this was made apparent when she smiled in amusement after Lena, her civilian boss and friend, refused to comply when Reign came to deliver her message to the world via CatCo's broadcast, rather than viewed the human as a standing obstacle to the cleansing that she was trying to effect (and the world killer would have killed her, just for that, on the most recent instructions received from the Fortress of Sanctuary) upon Earth, but went on with her purpose anyway and left Lena unharmed. Additionally, she rapidly took over and went immediately after Morgan Edge upon Sam learning that Edge staged an assault against Lena from days prior, hinting a protective (if not fiercely territorial) side of herself even as Reign.
Though this leniency of sorts oddly did not prevent her from attempting to go after Alex (whom Sam is also reasonably acquainted with) when the latter, J'onn and several of the D.E.O. operatives staged a futile ambush against the world killer - and had to be physically stopped by the Martian himself. Reign would later come close to killing Alex, knocking the latter down then stepping over to place a foot upon Alex's chest (though to be fair, at both confrontations, Alex clearly presented herself as Reign's enemy when she forced green kryptonite around the world killer's neck to bring the masked Sam down during first and then repeatedly fired several ineffective shots, in the second, with her gun at the latter) after telling the agent that she'll take her life then and there - only stopping at the beseech of Julia, who offers to be taken and become Purity completely on the condition that Alex was allowed to live.
The fact that Reign agreed to Julia's terms shows an honorable aspect on the part of the former not obligated to carry out every will of the Fortress of Sanctuary and would also not do anything as drastic as taking another's life without sufficient motive, since retrieving her fellow world killer, Purity, was her primary obligation at that time.
As Reign, Sam speaks in a disguised tone that ends her sentences in a reverberating manner.
Powers and abilities
- "There is no prison you can build that can contain me. There is no one on this planet of equal power that can kill me."
- —Reign to Supergirl[src]
- Dark magic-empowered Kryptonian physiology: Reign's physiology was altered due to genetic experiments and dark magic, courtesy of the Children of Juru. Normally Reign's capacities are no greater than a normal human of her host, Samantha Arias', physical conditioning, However, once charged by the energy of a yellow sun and metabolized into her body, she becomes able to perform a variety of otherworldly feats. Due to her dark magic enhancements, Reign's powers are naturally greater than any normal solar-powered Kryptonian. It is said that she was born from Rao's fire. According to Selena's hologram, Reign's powers are more advanced and potent than Supergirl, as proven by her decisive victory over the National City guardian. It's presumed that Reign is just as powerful as Superman, having been on Earth for at least 35 years. With her powers augmented to untold levels, Reign was one of the most powerful beings in the entire multiverse.
- Solar energy absorption: Reign's powers are not dependent on the energy spectrum from the yellow sun, but she can still fill her reserves with solar energy, augmenting her abilities, especially her heat vision. It is also possible that Reign could discharge all of the solar energy in her reserves.
- Enhanced memory: As a Kryptonian, Reign's memory is greatly enhanced, allowing her to remember specific details of her birth, the destruction of Krypton, and her creators, the Children of Juru.
- Super senses: All of Reign's senses are heightened to greater than that of a normal human.
- Super stamina: Reign can run or fight for long extended periods of time, and this aspect of her powers stem further than that of Supergirl.
- Accelerated healing factor: Reign’s metabolism is tremendously enhanced by solar energy, allowing accelerated healing abilities and burning calories at a fast rate, making her practically immune to becoming overweight.
- Contaminant immunity: Reign has an immunity to all forms of disease and contaminants. After absorbing Grace's abilities, she became immune to all forms of Pestilence as well.
- Flight: Reign is able to manipulate her own gravitational field to generate thrust and propel herself through the air, often at supersonic speeds, much faster than she can travel by foot.
- Super jumping/Leaping: Reign is able to jump several feet off the ground and leap vast distances through the air, simulating short term flight. This ability is a combination of super strength and flight. Reign is also able to jump very high and generate enough force to smash through windows.
- Heat vision: By concentrating every solar energy reserve she has in her body, Reign can emit focused energy beams of variable intensity and temperature from her eyes. Unlike other known Kryptonians, Reign’s are bright and searing red; it also appears to be more potent, as with it she was able to kill Livewire, who sacrificed herself to prevent Kara from getting hit instead. Her heat vision can also be used a lasers, rather than burning attacks.
- Invulnerability: Reign is essentially invulnerable to all Earthly weapons, with bullets simply ricocheting off her flesh. Her invulnerability is so intense that even when just beginning to manifest her powers, while in her good for Sam remained oblivious to being shot at Lena's press conference attack, only noticing the lack of injury a while later. While fighting Supergirl, as a fully transformed Reign, though she was repeatedly staggered from all of the former's powerful attacks, she’s rather quick to recover and retaliate - emerging with no signs of even being hurt or tired at the end. Sam would later fare the same against J'onn who, despite the Martian's attempt to entrap Sam by miles beneath the Earth by phasing her through the planet's surface, was forced back above ground by the Worldkiller' thrashing movement as J'onn extended his intangibility over to her; and even then, Sam still had enough strength in her to go up against a newly-revived Kara and was only forced to retreat after she got close enough for Supergirl to inject refined Green Kryptonite directly into Sam's deep neck muscle. It was later made evident that her otherworldly resistance to physical harm, like every other enhanced attribute at Sam's disposal, is not dependent on a yellow sun, since she was able withstand a brunt of Livewire's electric-based attacks and even serenely ignored a steadily rising voltage surging across her outstretched arm that the meta-human was directly trying to electrocute her with while Sam was holding Leslie fast by the neck, only finally breaking free from the Worldkillers' grip once the energy that Livewire was amassing reach critical threshold and propelling both of them away to opposite directions. However, Sam's invulnerability as herself seems to be greatly mitigated until her Reign persona takes over, expressing itself only when inflicted with something that would otherwise be borderline detrimental or life-threatening (i.e. gunshot) which explains as to how Alex was able to draw blood from Sam via a syringe.
- Self-sustenance: Due to the effects of a yellow sun, Reign's physical needs are greatly reduced or completely removed. It is unknown if a yellow sun's absence voids this aspect of her powers.
- Atmospheric adaption: While Reign does require oxygen, her physicality allows her to survive while inhaling more harsh forms of it.
- Longevity: As a Kryptonian, Reign's lifespan is considerably longer than a normal human and likewise ages much slower, and after absorbing Pestilence's powers, she should be able to live for a near-infinite amount of time, almost never aging.
- Electrosynthesis: Reign's body creates her own power source, thus her powers are not reliant on the yellow sun.
- Kryptonite immunity: Reign has a very high level of resistance to Kryptonite. This was proven when Lena’s supercharged Kryptonite was only able to weaken her. Though she is somewhat immune to Kryptonite, supercharged, or very potent forms can weaken her, or possibly even kill her, if she had enough exposure to it. She was even able to attack the Kryptonite from inside her body after she had stabbed in the jugular vein by Supergirl. Though she has a high tolerance to Kryptonite, it can still penetrate her skin.
- Temperature and elemental resistance: Reign can resist any temperatures, including heat and cold, as well as elements such as rocks and high levels of electricity, as shown when she was crushed by rubble, burned by Supergirl, and frozen by Lex’s mansion defenses. She is also impervious to any other elemental attacks.
- Super smell: Although she rarely uses this power, as an enhanced Kryptonian, Reign has the ability to pick up smells that are very far away or very subtle. She can also identify where the smell is coming from.
- Super vision: As a Kryptonian, Reign is able to see very far distances, presumably at peak human, or low superhuman levels. She is even able to see clearly in the dark.
- Electromagnetic spectrum vision: As a Kryptonian, Reign can see well into most of the electromagnetic spectrum. She can see and identify radio and television signals as well as all other broadcast or transmitted frequencies. Using this ability, she can avoid detection by radar or satellite monitoring methods.
- Microscopic vision: Reign has achieved the ability to see extremely small objects down to the atomic level, and magnify objects for her eyes to see.
- Telescopic vision: Reign possesses the ability to see something at a great distance, without violating the laws of physics. Though limited, the exact extent of the ability is undetermined. In function, it is similar to the zoom lens on a camera.
- X-ray vision: Reign has the ability to see through objects; except for lead.
- Infrared thermal vision: Reign has the ability to see heat and cold signatures of people and other objects. Reign can also see with better acuity in darkness, and to a degree in total darkness.
- Super breath: Reign is able to exhale powerful gusts of air from her mouth which are similar to force winds. She can also cause the temperature of her breath to drop, therefore able to freeze nearly anything. And after Imra telekinetically shielded her husband from Reign’s freezing breath, that inadvertently formed an ice dome around the Daxamite, it was seen that the ice she creates in this manner bear enough constitution to resist Mon-El's yellow sun-enhanced repeated strikes when he hopelessly attempted to break out of the solidice-sphere encasing him and keeping him hopelessly in place.
- Vocal alteration: As Reign, Sam usually speaks in a condescending reverberating manner, but by using her vocal alteration ability, she can turn her voice back to normal and vice versa. When using this power, the area around her throat glows a bright orange-red color. She first demonstrated this power by using it to trick "Patricia" and "Ruby" into thinking it was her human persona.
- Super hearing: Reign has super-sensitive ears that can perfectly pick up sounds from miles away and even through structures. Sam can also make her super hearing selective, and after absorbing Julia’s abilities, she immune to loud sounds, and can switch her super hearing on and off.
- Super speed: Reign possesses the ability to move at super-sonic speeds, both through flight and on foot. Her speed seems greater than Supergirl's, who despite being fast enough to intercept bullets, failed to evade the vast majority of Sam’s assaults, and even repeatedly outmaneuver the latter for the most part of their first battle.
- Super reflexes: As Reign, Sam's reflexes are so fast, she can respond to attacks within seconds, much faster than Supergirl can, as she has overpowered the latter in hand-to-hand combat repeatedly.
- Accelerated perception: When moving at super speeds, Reign is still able to take in everything going on around her, except much slower.
- Super strength: On the day of the revelation of the Girl of Steel statue, after a mysterious attack by Bloodsport, in a moment of desperation to save her daughter, Ruby's life, Sam raised an iron bar with little effort. After her awakening, Sam's full strength was proven to be considerably greater than Supergirl's, capable of feats like nearly overturning something as large as an oil tanker and punching away 31st Century artillery ordnance with apparent ease. While able to block some of Sam's blows, the repeated accumulation of hits that landed soon left Supergirl bleeding heavily and bruised all over, barely able to stand before finally falling into a coma and critical condition. It is unknown if Sam is stronger than Superman.
- Shockwave creation: By clapping her hands on stomping her feet with her super strength, Reign can create massive shockwaves, powerful enough to injure Supergirl. She can also use this to create a thunderclap effect, which generates so much force, it creates a large sound.
- Worldkiller link: The Worldkillers appear to have a link with each other using Reign as a nexus point. This is evident as no Worldkillers awoke until Reign did. Julia/Purity does not have children so this did not inhibit the development of her powers like Reign and only woke after Reign did. Along with the other world killers, Sam is able to create a full eclipse on Earth’s sun and generate a blue shockwave that was able to incapacitate Supergirl. Once Grace and Julia died their powers transferred to Sam, though Sam was able to apply both the Worldkillers' powers further than they did respectively.
- Sonic scream: After absorbing Julia Freeman's powers, Sam can vocally emit a focused, high frequency sonic scream that is powerful enough to knock a fully grown Kryptonian feet away into a wall. She has advanced with this power so that her scream is powerful enough to make Martian Manhunter bleed profusely out of ears, so much so he needed to be hospitalized.
- Sonic inducement/Sound projection: With a slight clench of her hands, Sam, is able to induce vertigo, vibration, and a sonic sound in her immediate vicinity, extending outwards omni-directionally. She has also used this power to create powerful sound shockwaves in conjuction with her scream.
- Empathy: After absorbing Julia Freeman's powers, Sam is able to "see" into people, and is able to read peoples personalities, and look deep into their psyches.
- Sonic scream: After absorbing Julia Freeman's powers, Sam can vocally emit a focused, high frequency sonic scream that is powerful enough to knock a fully grown Kryptonian feet away into a wall. She has advanced with this power so that her scream is powerful enough to make Martian Manhunter bleed profusely out of ears, so much so he needed to be hospitalized.
- Pestilence inducement: After absorbing Grace Parker's power, Sam can spread some kind of contagious virus that can kill any living thing she comes into contact with as seen when dozens of pigeons fell dead from the sky, when people at city hall started having nose bleeds before collapsing and when a plant immediately died upon being touched. According to Mon-El, it is 100% fatal. She has taken this power so far as she does not need complete physical contact with the organism, but just needs to be in the vicinity of it. She was even able to affect plants that were yards away from her.
- Retractable claws: After absorbing Grace's power, Sam can grow her nails into yellow claws, sharp and dense enough to pierce Supergirl's invulnerable skin, and presumably any other being. Her claws can also induce pestilence when she grows her nails upon physical contact. Her nails are retractable, and can reform to normal size.
- Evolution: After absorbing Grace's powers, Sam can "evolve" into more powerful and potent forms of herself, including turning into diseases and creating new ones. She has used this ability to passively evolve her body in order to become more resistant to larger doses of Kryptonite.
- Telepathy immunity: Reign can resist psychic attack with ease, but this power falls short against more powerful telepaths such as Psi.
- Psychic interdimensional travel: According to Lena Luthor, Reign is capable of travel psychically between dimensions, while Sam is awake, Reign is in the dark valley and vice versa.
- Bilingual: Reign is capable of fluently speaking English and Kryptonese.
- Expert hand-to-hand combatant: Though not particularly acrobatic beyond her capacity of self-propelled flight, Reign is a highly trained unarmed combatant. Able to effectively combine her raw might into her battle tactics, she can land efficient and devastating blows that very few could defend against. Ultimately, Reign was able to defeat and severely injure Supergirl, who received considerable combat training, and even render her foe comatose; she blocked and countered many of her fellow Kryptonian's blows while gradually wearing down Supergirl with her vicious strikes, even whilst soaring together with her in midair, until Supergirl was too winded and battered to fight back. Reign even fought J'onn J'onzz to a stalemate. As noted by Mon-El, Reign's combat skills mainly come from pure brute strength rather than actual training. However, Reign was still able to fight on par with Supergirl and Mon-El whilst they used their capes in battle.
- Reign suit: Reign wears a protective suit to hide her identity from her victims and opponents.
- Sword of Juru: Reign used the Sword of Juru in an attempt to complete Earth's terraforming. Later though, the sword was stolen and used by Samantha Arias to attack the Worldkiller.
- Reign and Selena are the main antagonists of season 3.
- According to Thomas Coville, the Worldkiller Reign's legend/prophecy existed long before the book of Rao.
- Reign's heat vision is red, as often depicted in the Superman comics and other media. In the show, Kryptonian heat vision is traditionally blue.
- If one counts her separation from Samantha Arias as a brief death, then Reign is one of the few individuals in the multiverse to come back from the dead without any means of time travel, the others being Sara Lance, Kuasa, Roy Harper, and Nate Heywood.
- Interestingly, all five individuals were brought back by some form of magic.
- In the comics, Reign was a Kryptonian biological weapon created by Supergirl's father, Zor-El.