Ocean Master

He appears in third episode "Evil under the sea!" It is shown in a flashback how Atlanna chose Aquaman over Orm as the new ruler of Atlantis. He allied with Black Manta to destroy Aquaman and become the new king. He was betrayed by Black Manta and fettered beside Aquaman. They managed to escape from their prison and fought with Black Manta henchmen. At the end of the episode, he stays in prison while Aquaman reads his adventures to him.

Origin
Ocean Master first appeared in Aquaman #29, introduced as Orm and was Aquaman's half-brother, son of Tom Curry (Aquaman's father) and a woman named Mary O'Sullivan. Orm had no super powers, being fully human, he was jealous of Aquaman. Designing a special suit that would allow him to operate underwater, he became a menacing pirate and terrorist and would often attempt to usurp Aquaman's throne.

When writer Peter David re-imagined the Aquaman mythos post- Crisis on Infinite Earths, Aquaman was no longer the half-human son of Tom Curry but rather his adopted son. This meant that Orm too was no longer a child of Tom Curry, but instead shared Aquaman's new father, the ancient wizard Atlan along with an un-named Inupiat woman. In Aquaman's youth, Arthur happened to rescue a woman named Kako, who was also Orm's cousin. The two developed a relationship which lead Orm to attack Kako out of jealousy.

Later, when Orm learns of his father, he wishes to overthrow Aquaman as the king of Atlantis, though he was not initially aware that Aquaman was his brother. After the New 52 reboot of the DC Universe, Orm is once again the half-brother of Aquaman. This time, however, he is the son of Aquaman's mother Atlanna. After she had birthed Aquaman on the surface world with Tom Curry, Atlanna was forced to marry a man of the Atlantean Guard upon her return, thus birthing Orm. After Orm's father's death, he kills his mother and seizes the Atlantean throne for himself. Orm, spear heading The Atlantean War, eventually yields the throne to Arthur, is abandoned to the top side to serve his time in Belle Reve prison while awaiting trial.

Power and Abilities
Orm's powers vary considerably based on the time and storyline.

''Early versions had him relying on gadgets and equipment that allowed him to function underwater. Making a deal with Neron, he possessed a trident that allowed him to become a sorcerer. Sometimes he is dependent on items for power, or even to function.''

From his brief appearances in the New 52, Ocean Master has shown that that he is a formidable opponent with a variety of powers.

Ocean Master is a fully bred Atlantean unlike his brother Aquaman who is only half-Atlantean which may account into Ocean Master having substantial superhuman abilities and/or enhanced levels of the powers. Ocean Master is the brother of Aquaman and therefore share similar genetics, thus should have most of the powers that Aquaman possesses.

Ocean Master has been shown to be able to lift a male of average height and build with one hand on the human neck. He can be considered a class 100 due to the fact that his brother is one as well. Ocean Master has a number of superhuman powers, most of which derived from the fact that he is adapted to live in the depths of the ocean, coherently having the ability to breathe underwater. He possesses superhuman durability, high enough to be unaffected by the immense pressure and the cold temperature of the ocean depths, this also makes him tough enough to be almost invulnerable to gun fire.

Ocean Master's enhanced physiology enables him to withstand heavy impacts that would kill any normal human being and gives him the ability to go far down the ocean floor. He possesses superhuman durability high enough to be unaffected by the immense pressure and the cold temperature of the ocean depths, this also makes him tough enough to be almost invulnerable to extreme heat and gun fire.

Orm also has the ability to hear and smell much greater than human capacity and possesses superhuman reflexes. His ability to see through murky, dark waters gives him remarkable vision at night while on the surface.

Ocean Master is a expertise of magic manipulation and can utilize it for many effects including magical bolts and telepathy.