- "For the last time... I am trying to save everyone! Don't you understand? You're not the hero here, I am!"
- —Ramsey Rosso to Barry Allen[src]
Dr. Ramsey Rosso, self-nicknamed Bloodwork, is the son of the late Rachel Rosso and a former friend of Caitlin Snow. His plans to create a cure for HLH using dark matter as a binding agent led to him becoming a meta-human. Despite his research and the best efforts of himself and S.T.A.R. Labs, he was unable to find a permanent medical solution to his condition, though he eventually came to the conclusion that he could live forever so long as he strikes fear into others and feeds on their adrenaline-infused blood, leading him to completely abandon his humanity in favour of self-preservation.
Ramsey, along with everyone else on Earth-1, was killed by Mobius when an antimatter wave hit the planet; however, due to the Paragons and Spectre, he was resurrected on Earth-Prime. He is currently being held by A.R.G.U.S. and has unknown plans; he states that he is in for the "long run".
When Ramsey was seven, he hurt his knee in a biking accident. He felt extreme pain and wanted to give up, but his mother encouraged him to never give up despite the pain. Years later, this would become a defining incident with Ramsey and his personality. He eventually followed in his mother's footsteps and became a doctor, working alongside Caitlin Snow until she left to join S.T.A.R. Labs on his mother's recommendation.
Eventually, his mother was diagnosed with HLH cancer forcing Ramsey to watch as his mother's life slowly faded over the course of months. However, instead of fighting the cancer, Rachel Russo instead spent her remaining time doing the things she most wanted to do in life. This particularly angered her son who felt she was being cowardly by not fighting her cancer. Rachel then passed away, leaving her son with lingering feelings regarding death and lab results that showed a 99% chance he would have the same cancer she had.
Ramsey relentlessly researched a cure for himself, running countless simulations that all came back with the same result - that he needed dark matter to complete the cure. Knowing that Caitlin was still employed at S.T.A.R. Labs, a known producer of dark matter, he invited her to his mother's funeral. There, they exchanged pleasantries and Ramsey brought up the idea of meeting again under the guise of friendship.Caitlin eventually agreed to share coffee with him and they met at CC Jitters. Ramsey quickly moved the conversation about his mother to his research, letting Caitlin know that he needed dark matter to finish it. Caitlin repeatedly objected because it would cause unknown risks, angering Ramsey and causing him to leave the coffee shop. Now being forced to find dark matter elsewhere, Ramsey purchased a dark matter powered weapon off the black market. Taking the dark matter he needed, Ramsey injected himself with the cure. Initially, it seemed to work, but things turned horrifying moments later, mutating Ramsey into something else.
Dealing with Mitch Romero
Despite injecting himself with the cure, Ramsey wasn't completely cured. He sought out another dark matter weapon, only this time his dealer was Mitch Romero. Mitch informed him that the price had jumped from $500 to $5000, when Ramsey informed Mitch that he didn't have the money a fight broke out when Ramsey attempted to take the weapon from Mitch. Mitch knocked him to the ground, leading to Ramsey activating his powers in a moment of distress and exposing Mitch to an unknown substance that ultimately killed him.
Ramsey discreetly took Mitch's body back to his lab, where Mitch resurrected himself and knocked out Ramsey. Ramsey then awoke the next morning to find Barry Allen and Caitlin interrogating him over a dark matter theft that the undead Mitch committed. Ramsey lied, informing them that Ted Kord gave him dark matter and that Mitch broke in and attacked Ramsey. He then manages to convince Barry that he could help their investigation by analyzing a blood sample they found at a crime scene. After some verbal sparring between him and Caitlin, Barry gets a call that Mitch has broken into Mercury Labs.
After Barry brings him a sample of Mitch's blood, he discovers that while the dark matter enhances Mitch it also destroys the healthy cells. Barry informs Ramsey that Mitch has been dead for over 24 hours and starts to leave before Ramsey pleads with Barry to take him with on the investigation. Barry reluctantly does and brings Ramsey to S.T.A.R. Labs to develop a way to beat Mitch.
Ramsey explains to Barry that he could use gene-splicing to weaken Mitch long enough for an arrest, but informs Barry that he'll need more supplies. Barry then leaves the room, allowing Ramsey to steal some dark matter. Barry comes back, revealing that he suspected Ramsey would try something like what he was doing. Ramsey angrily retorts that he's dying and that the dark matter is the only way to cure him, something Barry should understand as he knows the look of a dead man. Barry manages to convince Ramsey to give back the dark matter and help them defeat Mitch.
Later that night, Ramsey continued to study Mitch's blood sample that was mystifying him. Suddenly Ramsey heard a noise and went looking for the source, discovering that Mitch had snuck into S.T.A.R. Labs, who attacked Ramsey shortly after. While being strangled up against a wall Ramsey pleaded with Mitch to stop which, much to Ramsey's shock, worked. After being lowered to the floor Ramsey discovered that Mitch was responding to his voice and visual commands, before Barry rushed Mitch down to the Pipeline and defeat the zombie-like creature.
The ordeal over, Ramsey left S.T.A.R. Labs and took a sample of Mitch's blood with him. He observed immense healing properties and hypothesize that this was the permanent cure he was looking for. He then proceeded to absorb the blood before concluding that he needed more.
Sometime afterward Ramsey broke into a blood bank at a hospital, stealing the blood and taking it to his lab. There, on the verge of collapsing, he injected his mutated blood into the regular blood in the hopes that it would create the same substance from Mitch Romero. Hours later, he injected himself with the new version of the cure but collapsed in pain shortly after injecting it. He discovered that his new cure lacked something that Mitch Romero had before death.
Barry then dropped by with a cure made from Dominator technology leftover from their invasion three years prior. This left Ramsey stumped as he knew Barry himself was dying and that this cure could work for him too. Barry just responded that Ramsey could save lives as well before leaving. Ramsey took a sample of the Dominator cure and injected it into a sample of his cells, dismayed to discover that his body was too far gone for the cure to work. Suddenly he made a realization, Mitch was afraid at the time of his death and thus was releasing adrenaline into his system before death. Ramsey concluded that his victims need to feel fear before he kills them, disregarding the Hippocratic oath that hung above his lab. He arrives at a hospital and starts killing patients and doctors alike.
Long into his killing spree, Flash and Killer Frost arrive to see the damage he's done. While Killer Frost fights his reanimated victims Flash confronts Ramsey, asking him why since he was handed a cure. Ramsey takes a hostage and explains that the cure didn't work, so he decided to use living people as incubators for his cure. He explains that he hasn't just found the cure for HLH but for death itself, making him life eternal. He kills his hostage and escapes through the window, satisfied with his efforts but nowhere near done.
Some time after strangling Caitlin and leaving his lab, he encountered Ralph Dibny on a rooftop, grabbing him and falling off the building with him. As soon as they fell to the ground, Ramsey continued attacking Ralph, throwing a car at him and firing chunks of black blood at him, most of which the latter was able to dodge, but not for the last few. Ralph managed to gain the upper hand by punching Ramsey and attempted to take him to Iron Heights before Ramsey recovered and absorbed the former's healthy blood cells with his own blood, leaving him on the ground convulsing.
When Barry managed to save Ralph's life by injecting some of his blood into him, a tiny amount of Ramsey's blood had made its way into Barry's body, slowly taking control over him and turning him into a monstrous speedster, who made his way to see Ramsey before bowing to him as his follower, or in Ramsey's words, "Blood Brother".
Defeat and Imprisonment
With Dark Flash now under his control, Ramsey sets out to infect the whole of Central City. He comes under attack from Cisco Ramon, but he uses Dark Flash to stop him. Ramsey tells Cisco that he wants to use the S.T.A.R. Labs particle accelerator to spread his "cure" across Central City. He and his Blood Brothers head to S.T.A.R. Labs, where Ramsey puts a tiny amount of his blood into the accelerator. However, before it can complete its cycle, Allegra Garcia used her powers to destroy Ramsey's blood; causing the wave created by the explosion to curing all of the infected. The newly-recovered Flash fights Ramsey, who transforms into a huge blood monster. Flash uses the mental link Ramsey had created between them by infecting Barry to make an image of Ramsey's mother to appear. This distracted Ramsey long enough for Flash to lock him up in the MAC. He was then transferred to A.R.G.U.S..
During the Anti-Monitor Crisis, Ramsey as well as everyone in the multiverse except for the seven Paragons, was killed in an antimatter wave by the Anti-Monitor on December 10, 2019, only to be restored a month later, after the Paragons and the Spectre created a new universe.
- "Even in here, fate continues to cast me in the role as savior."
- —Ramsey Rosso[src]
to obtain his mutated blood for Eva's plan to escape the Mirrorverse. He agreed to let Eva take some of his blood in exchange for his freedom. Mirror Kamilla sacrificed herself to destabilize the MAC long enough for Ramsey to temporarily escape. He attacked Mirror Iris, demanding to know what she really wanted. When Mirror Iris stated that she wished to be "alive", Ramsey gave her some of his blood. He then willingly stepped back inside the MAC, lamenting that he has more than one way to escape, and that he was playing the "long game".
While seemingly once a noble man who with a strong devotion to the protection of life, Ramsey's true nature can be defined by his obsession and fear of death. Watching his mother die without fighting her cancer caused Ramsey to develop an intense obsession with defeating death. And his mother's acceptance of death caused him to label her a coward, for not taking a chance to fight and survive. Ultimately it was a fear of death that pushed Ramsey to extremes in developing a cure for cancer then testing it on himself, despite advice being given to him about its possible adverse effects. His new obsession strained his friendship with Caitlin Snow.
A short time after developing his powers and learned how it could extend his life and potentially grant him eternal life, Ramsey quickly went down a sinister path. Despite Ramsey having a copy of the Hippocratic oath hung up in his lab, he is proven to have no value to the quote "I will do no harm to others" and proceeded to break the oath. Having seen a victim of his powers produce a healing substance from the fear-induced adrenaline in their blood, Ramsey became determined to create more no matter the lives it costs.
Through his descent into madness, Ramsey has developed both a delusion of grandeur and a messiah complex. For all his remorseless killings of innocents, he ironically views his actions as a salvation for humanity. By reanimating his victims as zombies in a hive-mind of his control, he believes that this is the way to forever overcome death for all. Ultimately, this has made Ramsey's goal to infect every human on the entire planet and get them to pledge their full loyalty to him.
Ramsey appears to hold life in high regard still. This is evident by his horrified reaction when "Kamilla Hwang" intentionally killed herself to free him from his cell; he found the act of killing one's self to be unthinkable. To him, choosing to die is an act that not even him is comfortable with. As such, he seems to justify his killing by both thinking that these people are not intentionally choosing death, and that he is actively choosing to live. Ramsey can view not killing his victims as him purposefully choosing suicide, further establishing his twisted views on life and death 
He also seems to still possesses some pride and brilliance, despite his near inhuman state. When the mirror duplicates were explaining who Eva McCulloch is, Ramsey angrily retorted that he knew who she was because, he too, was a scientist, hinting that he still views his former profession as a prestigious one. His calculating mind also came through, in that, despite being free of his cell, he would never escape A.R.G.U.S. (Earth-Prime). Instead, he choose to sit and wait, plotting out another plan.
Powers and abilities
- Meta-human physiology: After injecting himself with the untested HLH cure infused with dark matter, this supercharged Ramsey's blood cells, allowing him to access his new-found powers.
- Haemokinesis: Ramsey possessed the power to control and manipulate blood. Through this power, Ramsey could also absorb the blood of others to heal or empower himself.
- Blood constructs: Ramsey was able to rearrange his blood cells and transform them into different objects. He has thus far been shown to transform them into elongated tendrils that can penetrate human skin, which he used to take blood from others and as a means of transportation. He could also fire off small pieces as projectiles.
- Power augmentation: By absorbing the black blood that he fills his victims/zombies with, he was able to temporarily heal himself of his HLH, as well as increase his own power and his blood mass; allowing him to make larger blood constructs in his blood form. It also showed in his physical appearance, as his veins became noticeably darker as a result of the dark matter-infused blood.
- Reanimation: When Ramsey used his abilities to take blood from others, he was able to leave a trace amount of his own dark matter-infused blood in their system, which would replicate itself and replace the blood of the victims, reviving them as a violent and lumbering "zombie" that followed Ramsey's desire for dark matter, with him having full control. Shortly after he learned that he could turn people into zombies, he found out that he could also command and control the zombies, however, a zombie that is left without dark matter being injected into them or without Ramsey nearby will melt into a pool of black blood
- Superhuman strength: Ramsey was shown to have a remarkable amount of strength, as he demonstrated the ability to break open a lock with his bare hand when stealing blood from a hospital. He also single-handedly lifted Caitlin Snow off her feet while strangling her. When he attacked Elongated Man, he threw a car at him.
- Infection: Ramsey was able to create another mind of himself through infecting others with his own blood without having to absorb their healthy cells, changing their personalities and turning them into monsters that pledged their full loyalty to Ramsey himself; as shown when Barry became fully infected through his eyes and teeth being filled with black blood, his lighting turning black, and his being forced to follow Ramsey's commands.
- Power bestowal: When Ramsey infected someone with his blood, they gained several powers such as; superhuman strength, long black finger nails, and the ability to absorb dark matter. In Barry's case, he also gained a mental connection, allowing Barry to make Ramsey see a hallucination of his mother.
- Mind manipulation: Ramsey's blood had the ability to infect human brains and project hallucinations to its victims, as shown when Barry was hallucinating. This ability also allowed Ramsey to perceive his victims thoughts.
- Transformation: After feeding on enough blood, Ramsey transformed into a monstrous, hulkish form, which appeared to be skinless. Apparently, this form was stronger than his human form. In Ramsey's monster form, he could morph his hand into a blade that effortlessly cut through a van.
- Haemokinesis: Ramsey possessed the power to control and manipulate blood. Through this power, Ramsey could also absorb the blood of others to heal or empower himself.
- Dark Flash's powers: After infecting Barry Allen, Ramsey could access his powers, such as using his speed and his ability to phase.
- Genius-level intellect: Ramsey was an exceptionally intelligent individual; possessing a doctorate.
- Master Scientist/Medic: An accomplished biologist with intricate knowledge of the human anatomy and physiology, with Barry even calling him among the most brilliant doctors on the planet, Ramsey was capable of experimenting on himself in order to find a cure for his HLH cancer and coming into the conclusion that he needed dark matter to complete the cure. He was able to successfully analyze Mitch Romero's blood to discover the effects of dark matter on his body and with the supplies of dark matter, he was able to use gene-splicing to help Team Flash defeat him. He was smart enough to know that putting his blood into the S.T.A.R. Labs particle accelerator would cause it to aerosolize. This would have allowed him to spread his infection instantly to everyone in Central City and at a much faster rate than having to use his Blood Brothers.
- Expert of deception/Manipulator: Ramsey was a very good actor; he was able to act like a civilized doctor when around others without them suspecting anything.
- Insatiable hunger: Despite Ramsey managing to cure his HLH, the effects were only temporary. As a result, Ramsey needed to feed on dark matter infused blood. In order to keep himself alive, he needed to feed off of human beings with adrenaline-infused blood. Therefore; he had to put his victims in a state of great fear before he absorbed their blood, killing them in the process.
- Mental instability: Ramsey's obsession with defeating his impending death defiled his humanity. He eventually came to only care about surviving and nothing else. The more individuals he killed, the more unstable he became.
- Constant movement: In order for Ramsey to keep as much blood pumping around his body as possible, he needed to be constantly moving. The less he moved and the calmer he was, the weaker he became.
- Photon Gun: Cisco theorized that his gun could cure Ramsey or kill him and while he used it on him it showed that it could temporarily weaken him and stopped him from using his powers, though it didn't work on Ramsey nearly as well as Cisco had hoped.
- Mental link to Blood Brothers: Just as Ramsey was able to affect Barry's thinking using a mental link, after being infected by him, Barry was able to do the same to Ramsey. He used an image of Ramsey's mother to distract him long enough so he could lock Ramsey in the MAC; the only thing Team Flash was certain would be able to contain him.
- Electromagnetic Waves: EM waves were crucial in severing Bloodwork's link to both Barry and the other zombies. That weakened him a bit.
- UV rays: When Ramsey put his blood in the S.T.A.R. Labs particle accelerator to create an explosion that would turn all of Central City into Blood Brothers, Allegra Garcia releasing her UV rays into the accelerator caused the particle accelerator's explosion to release a wave that cured all the Blood Brothers Ramsey had already infected.
The Chronicles of Cisco
- Ramsey was the:
- Second main antagonist in The Flash to not die during his defeat, the first being Hunter Zolomon. However, Ramsey has not been cured of his illness so his death could happen in the near future.
- Fourth main antagonist to not receive his powers from the particle accelerator, after Eobard Thawne, Orlin Dwyer, and Grace Gibbons.
- First main antagonist to not have been created or influenced by the actions of Eobard Thawne.
- His mutated form was similar to the monstrous form of Rudy Jones/Parasite.
- His story paralleled Barry's struggle surrounding the Crisis.
- Both had lost their mothers.
- Both had shortened lifespans, though while Barry accepted his destiny, Ramsey hoped to prevent his impending death.
- While learning of his impending death propelled Barry to save as many people as possible, Ramsey's inability to find a cure lead him to give up his Hippocratic Oath, instead saving his own life before the lives of others.
- He is similar to Freddy Krueger as both need fear to stay alive both would hunt down people scaring them first and once they had enough fear they would kill them to increase their own powers. Freedy would absorb their souls while Ramsey would absorb the blood of his victims after infecting them to increase his own life.
Behind the scenes
- In the DC Comics, Bloodwork was an enemy of the Flash who had the power to control blood. His first appearance in the comics was The Flash #29 (October, 2017).
- Sendhil Ramamurthy also portrayed a doctor/scientist on NBC's Heroes, Dr. Mohinder Suresh. His Heroes character also gained powers through injection that was missing an ingredient at first.
- The Speed Force stated Ramsey's power could protect him from antimatter. Even if this remained true after his capture, Ramsey would have died from a lack of oxygen due to the destruction of Earth-1.
- Ramsey served as the main antagonist of the "Blood and Truth" arc the of Season 6 of .
- Ramsey is the first "big bad" in The Flash to start out good and descend into villainy over the course of his arc, rather than having already been a villain prior to the start of the story.
- He is the last Earth-1 Big Bad to name himself, before the Crisis rebooted it into Earth-Prime.
- Zoom, Savitar and Cicada were the only other Big Bads to not be named by Cisco.
- Like Cicada, he was one of the villains who's names Abra Kadabra did not say when he mentioned the names of the Big Bads Barry fought or would fight.