Ocean-Master is a scheming mastermind, not above playing people (like the purists) to fit his greater plans. He uses his secret identity and role in the royal family to further his goals; his position as the loving and caring brother of the monarch also ensures that he does not raise suspicions.
Ocean-Master dons a purple suit of armor with a cape. The suit of armor consists of spaulders, protecting his shoulders, and fingerless gauntlets and greaves, covering his forearms and shins, respectively. He walks barefoot. He also has a belt adjoined by an upside-down crescent moon, and wears a helmet that covers his face, leaving only his mouth visible. His eyes are covered by two round opaque red lenses. His suit of armor has an aquatic motif and features protuberances shaped like fins on the greaves and shreds and rips on the base of the cape, making it resemble a caudal fin. Underneath the armor, he wears a black jumpsuit.
Outside of his armor, Prince Orm resembles a tall, black-haired Caucasian male with a strong build. His hair is relatively short and slicked close to the head, but comes down to the nape of his neck, and he has long sideburns. His eyes are blue. He wears a black and dark red sleeveless tunic and a wide gold collar combining a close-fitting, round, and high collar around the neck (like a turtle neck) and an usekh-style collar on the shoulders. Orm also wears a wide gold belt with a stylized sea creature at the front and golden bracers.
Prince Orm nursed a grudge against his brother, and adopted the identity of the super villain "Ocean-Master". One day, he led an army against Poseidonis. There, he engaged Aquaman in battle and managed to emerge victorious. However, thanks to the intervention of two students from the Conservatory of Sorcery, Kaldur'ahm and Garth, Ocean-Master was occupied long enough for Aquaman to recover his strength and vanquish his opponent.
At some unspecified point, he joined the ranks of the Light and became L-5.
When Atlantis was attacked by Black Manta's forces, Orm remained behind to protect Queen Mera while Aqualad went to protect the Science Center. However, unbeknownst to everyone, he was the true instigator of the attacks. The goal was to take the echinoderm, but if that failed, the attack could serve as an excuse to move it to the surface world.
In his secluded lair, Ocean-Master debriefed his Atlantean purists on their efforts to terrorize "impure" Atlanteans. He declared that it was time for action, especially because the King was away. He figured that, being a pure Atlantean himself, his brother would approve of their plan: to purge Atlantis of the impure. Before deploying his minions, he allayed their fear of Aqualad, but warned them to be ready nonetheless.
Poseidonis September 6, 23:45 UTC-2
After the Atlantean purists successfully infiltrated the Poseidonis palace, Ocean-Master had his troops take her to their cave. He would deal with Aqualad, Superboy and Miss Martian himself. Because the palace had magic spells barring the use of magic, Ocean-Master waited until they were outside. Then, he unleashed the power of his trident on them.
With the queen safe in his hideout, Orm shed his armor, and set in motion the next phase of the plan to get rid of Aqualad. His "sources" found two possible locations for purist cells. He would investigate one, and Aqualad the other. He staged an ambush for them at the Old Roman's Trench.
With Mera at his mercy, Ocean-Master used his trident to drain her life force. She begged him to spare her and her unborn child to no avail. He explained that his goal was not to purge Poseidonis of its impure influences, but to create a civil war between the capital and the other city-states. Ronal overheard this and turned on his former master. But neither he, nor Aqualad and his friends, could defeat Ocean-Master now that he had Mera's sorcery at his command. But when Garth summoned the power of the Tempest, Ocean-Master briefly lost his grip on the trident. Mera's life force was restored, and Ocean-Master was forced to retreat.
Poseidonis September 7, 07:01 UTC-2
King Orin had returned from his mission with the Justice League, and thanked Aqualad and his friends. Orm reassumed the role of good brother by swearing to bring those who gave him false information to justice.
After the arrest of the Injustice League, Ocean-Master was present with the other members of the Light to hear Vandal Savage's view of the Kobra Venom Plant test and the heroes believing they had exposed the Secret Society.
Ocean-Master is the villainous half-brother of Aquaman, who attempts to seize the throne from the half-Atlantean Orin. He feels that, as a full Atlantean, the throne should be his.
This is Prince Orm's third animated appearance, and Ocean-Master's second. Orm previously appeared in Justice League and Batman: The Brave and the Bold. His villainous alter-ego Ocean-Master made his animated debut in Batman: The Brave and The Bold.