Rhea

"I crossed an ocean of stars looking for my son. I'm not going to let you get in my way now."

- Rhea to Kara

Rhea is the Queen of Daxam. She is also the wife of Lar Gand and the mother of Mon-El. She rules what is left of the Daxamites after the planet was ravaged by the debris of the destroyed planet Krypton. She is driven to have vengeance against both Kara and Earth for turning Mon-El against her.

Biography
When Daxam was hit with the debris of the destroyed planet Krypton, Rhea fled the planet alongside her husband Lar Gand as well as an assortment of other Daxamites aboard their prime ship. They survived off-world for years and learned that their son Mon-El was alive. They searched from the Well of Stars and then later Maaldoria where they learned that Mon-El was on Earth. They then journeyed to Earth when Rhea and Lar Gand began to notice that the yellow sun was having an effect on them.

When they settled in the atmosphere of the planet, they sent a message to Earth for Mon-El to be given back to them, under the belief that he was being held against his will. When Supergirl flew for their ship, they believed that she had come to attack them and had the ship's weapons lock in on her. However, Mon-El sent a message to stand down as he would give himself to them. They transported him and Kara to the ship where the three of them were finally reunited. At dinner, Rhea told Mon-El of their trials in trying to find him and praised the fact that Mon-El managed to survive. During dinner, there was also some moral debating exchanged with them and Kara when the topic of their slaves came up after mentions of Mon-El and Kara's heroics on Maaldoria. They then revealed to their son that Daxam's atmosphere was hospitable again and were going to return and rebuild their society again. However, Kara and Mon-El excused themselves back to Earth.

Later, Rhea went to the D.E.O. to speak with Kara about convincing Mon-El to return to Daxam to reclaim his birthright as the prince of Daxam. She told Kara that if he stayed then Mon-El would only be cruelly reminded that he was not good enough for her. She also pointed out that now that she knew Mon-El was royalty, she despised him for it and she needed to do what was best for Mon-El which was convince him to go with his parents. When Mon-El returned to the ship, Rhea and her husband believed that he was joining them to return but he instead told them that he was staying on Earth and that they should leave. Rhea accused Kara for his behavior but he angrily told her that being close to Kara made him want to be a better person and that she and Lar Gand didn't truly care about their fellow Daxamites at all. He then left the ship leaving Rhea and Lar Gand to angrily go over what just happened.

When a bounty was issued against Kara, Mon-El summoned both of his parents to the Alien Bar. She and her husband were surprised to find that he was a bartender but he claimed that it a humble and satisfying job which Rhea audibly doubted. When Mon-El brought up the bounty Lar Gand quickly denied that they had anything to do with it. When asked why they were still on Earth, they both said that they were hoping that he would change his mind and return to Daxam with them. Lar Gand pointed out that if not for Rhea's strength in the time that he was gone, the both of them would've sunk into despair.

Rhea was called by both Mon-El and Kara to the Fortress of Solitude where she was less than happy to be in a place that was reminiscent of Krypton. They revealed that they knew that she was the one that issued the bounty as one of the bounty hunters they faced ratted her out. They both tried to appeal to Rhea to allow Mon-El to stay as he had found happiness and meaning on Earth but Rhea claimed that what Mon-El found in his tryst with Kara was an illusion and it was over. She then revealed that she had Kryptonite weapons due to the amount that now littered Daxam and used it against Kara. Mon-El quickly moved to stop his mother from killing her and said that he would return to Daxam with her if she stopped and didn't hurt Kara anymore. When she was assured that she had his word, the two of them returned back to the ship. Once there, Mon-El told her to call off the bounty which she did immediately. After Mon-El was escorted away, Lar Gand approached her as he was surprised that she was the one that issued the bounty after all. She defended her actions as she had been trying to get her son back.

When Mon-El was trying to reason with his father on making changes to how they were to rule Daxam, she went over and slapped Mon-El into silence. She told him that it would take four years to return to Daxam and she wanted Mon-El in a cell with the hope that it would drive away Kara's influence on him. She then ordered for the ship to take off as soon as possible as she wanted to finally leave Earth. Before they could leave, Kara returned to the ship to get Mon-El back. Rhea and her guards confronted her but she was shocked when her Kryptonite had no effect on her. It was revealed that it wasn't Kara but J'onn J'onzz she had been fighting. Soon, the real Kara arrived to help and Rhea moved to fight her as her husband moved to confront J'onn. When she had Kara pinned and was ready to kill her, Mon-El ruptured the ship's window to suck out her Kryptonite weapons. Lar Gand then called for the fighting to stop as he saw that Mon-El made his choice.

Powers

 * Daxamite physiology: Normally, like all Daxamites, Rhea's capabilities are no greater than a normal human of her physical conditioning. However, once charged by the energy of a blue or yellow sun and metabolized into her body, she becomes able to perform various inhuman feats. While generic for her race (as well as for Kryptonians), upon arriving on earth for a short amount of time it is unknown whether he will develop other powers.
 * Solar energy absorption: While Rhea's powers are dependent on the energy spectrum from a blue or yellow sun, her body is able to constantly and passively absorb such energy while exposed to it, essentially keeping her reserves fully charged near-constantly. Direct exposure to sunlight will also accelerate her recovery from any injuries she does manage to sustain.
 * Accelerated healing factor: Rhea's solar charged metabolism accelerates her healing and allows her to burn calories at a fast rate, making her resilient to weight gain.
 * Electrosynthesis: Rhea's cells harness and absorbed the electrical energy surrounding her, manipulating it to regenerate herself at a cellular level and manifest her own energy source.
 * Contaminant immunity: Rhea has an immunity to all forms of disease and contaminants on Earth.
 * Super leaping: Rhea is able to perform incredibly high jumps in a single bound.
 * Invulnerability: Rhea is essentially invulnerable to all Earthly weapons. She is able to take far more damage than any normal human.
 * Super speed: Rhea possesses the ability to move at incredible speeds, far greater than that of any normal human.
 * Super strength: Rhea's strength is enhanced under a blue or yellow sun, enough to easily kill a normal human if he were to attack them directly.

Weaknesses

 * Lead: Rhea has a weakness to lead; if lead stays in her system for too long, she will die from the poisoning.
 * Extreme energy: Extreme amounts of energy can be enough to kill Rhea.
 * Red Sun energy: Like Kryptonians, exposure to the Red Sun will make Rhea the equivalent of a human being on Earth.
 * Magic: Rhea is not invulnerable to magic because her powers come from her natural physiology and not supernatural means.

Former equipment

 * Green Kryptonite-laced sai: When fighting Kara Zor-El, Rhea wielded twin sai laced with Kryptonite that were able to pierce Kara's skin and severely weaken her. She used them in her battle with Kara at the Fortress of Solitude and again during the D.E.O.'s rescue mission to retrieve Mon-El onboard the Daxamite spaceship. Rhea lost the sai when a hole was blown in the ship's throne room window, sucking the weapons out into the vacuum of space.

Behind the scenes

 * There are two characters in the DC comics named Rhea: the first one is the Titan revered as the Goddess of Earth, a supporting character of Donna Troy from the Teen Titans; the other is Rhea Jones, the electromagnetic heroine Lodestone, a member of Doom Patrol. Both of them seem to be unrelated to the show's Rhea.
 * In Greek mythology, Rhea is the wife of Cronus, the leader of the Titans, and mother of many of the gods including Hades, Poseidon, Hera and Zeus. She is responsible for Zeus's survival and overthrowing of her husband, since she hides him away to protect him from his father, who, in response to a prophecy, eats all of his children at birth.