- "You were the reason our mother was executed. And I've hated you for it ever since. But I do not want to kill you, Arthur. I'm going to give you one chance. Go home. Do not ever come back to Atlantis. You are not going to win this. A war is coming to the surface whether you like it or not. And I am bringing the wrath of the seven seas with me."
- ―Orm Marius to Arthur Curry[src]
Orm Marius was the king of Atlantis and Arthur Curry's half-brother. As the ruler of Atlantis, Orm was a skilled warrior who sought to unite the Seven Kingdoms as the Ocean Master against the surface world, due to humanity's pollution of the seas, but he failed and was defeated and apprehended by Aquaman.
Born to King Orvax Marius and Queen Atlanna of Atlantis, Orm became a great warrior under the guidance of chief counselor Nuidis Vulko. At the same time, he developed a strong hatred for the surface after witnessing the damage they were inflicting on the oceans, which is poisoning the Atlantean children.
Rise to Power
After taking his father's place on the throne, Orm began devising a master plan that would both unite the seven kingdoms and destroy the surface in one fell swoop.
Sowing the Seeds
In order to carry out his plan and become "Ocean Master", Orm had to obtain the support of at least four kingdoms of Atlantis. In his first bid to gain Xebel's support, he employed the aquatic mercenaries Jesse and David Kane to hijack a submarine and stage a fake attack on both Atlanteans and Xebellians during a meeting at the Council of Kings. In doing so, he used the seemingly unprovoked attack from humans as a pretext to both gain Xebel's support and declare war on the surface.
At the same time, some people close to him - such as his Vizir, Vulko, and betrothed, Princess Mera of Xebel - sought to avoid his planned war with the surface. Together, they hatched a plan to journey to the surface to ask Arthur Curry, Orm's elder half-brother for help in both stopping the coming war by becoming the King of Atlantis himself.
Meeting Arthur and Duel in the Ring of Fire
- "You have our mother's trident; powerful...but flawed, like her. I wield my father's...and it has never known defeat!"
- ―Orm Marius to Aquaman[src]
After arresting Arthur for illegally sneaking into Atlantis, Orm finally met his elder brother in the throne room of Atlantis, where he both explained his reasoning for his war against the surface and blamed Arthur for Atlanna's execution, since her crime was having a half-breed son.
While he offered Arthur an opportunity to leave forever, a provoked Arthur instead challenged him to a fight, which Orm interpreted as invoking the Combat of the Kings. This combat took place in the ring of fire, an ancient amphitheater surrounded by lava. After a decent fight, Orm gained the upper hand, destroyed Atlanna's Trident, and nearly killed his brother before Mera intervened and escaped with Arthur.
Preparing for War
- "Princess, prepare your armies...we move against the Brine Kingdom at once."
- ―Orm to Princess Scales [src]
After he realizes that both Kane and his Men of War failed to bring down Mera and Arthur, Orm also turned on Vulko and revealed that he knew he had been supporting Arthur all this time. After imprisoning him upon revealing his betrayal, Orm further prepared to launch an attack against the Kingdom of the Brine, the last kingdom he needed the support of to earn the title "Ocean Master". 
- "Join me or die!"
"And you'll expect me to address you as 'your highness?'"
"Not Your Highness. Call me... Ocean Master."
- ―Orm and the Brine King[src]
With only the Kingdom of the Brine left to bring to heel, Orm led the full forces of Atlantis, Xebel, and the Fishermen kingdom into battle against the Brine. In the midst of the onslaught, Orm engaged the Brine King and came close to dealing the death blow, only for Nereus to intervene and remind Orm that they needed the King for their plans. After the Brine King defiantly refused to ever swear his allegiance to him, Orm moved to execute him, only to be for the ground to burst open as the Karathen emerged from the earth's core, ridden by Arthur wielding the Trident of Atlan.
Orm ordered his forces to focus their fire on the newcomers, but the Karathen proved too strong and Arthur's ability to command the entire sea and summon an army of sea creatures (including the Trench) eventually overwhelmed their combined forces. Additionally, due to his possession of the trident and said ability to command the sea, the forces of Atlantis began to accept Arthur as the true king, instead of Orm.
- "That trident doesn't change what you are - a half breed bastard. Atlantis will never accept you as its king."
- ―Orm to Arthur[src]
Ever since that he was born, Orm Marius has been raised on the values of being a great king as well as been guided by Vulko to become a magnificent great warrior, allowing him to develop great skills of warfare. As Orm rose to the surface world to learn about it, he has become known to the massively great damage that the human race and the surface are causing to the Seven Seas with pollution, factories and trash, driving him into developing a psychotic obsession to destroy them all including the surface world in order to save Atlantis from extinction.
After the death of his parents, Orm has become the new king of Atlantis, and began devising a wide master plan to destroy the Earth and humanity by uniting all of the kingdoms underneath the sea into a great war.
Ruthless, manipulative, bold and above all powerful, arrogant and murderous, Orm has been doing multiple stages such as hiring the services of the human mercenary David Kane into killing his brother and manipulated King Nereus and others into assisting his war, becoming the "Ocean Master". Nereus of course supported him but Mera has never wanted in Orm as the king, causing Orm great hatred for her and to send a tidal wave to erase a part of the surface but Mera used her powers to stop it. His rule can be described as both dictating and tyrannical, as he shows no qualms in putting those who did not agree to his plans in place and even kills the Fisherman King just because he was not a chance of good fighting in the war. All of this was for the ultimate goal for destroying the surface world by unleashing the wrath of the seven seas.
Orm is not purely evil by his nature, however, and his goal is not to seek power for himself by having Atlantis conquer Earth but instead to save Atlantis from the damage the humans could potentially deal, in much the same way as the deceased General Zod had attempted to create a new Krypton on Earth. In addition, he genuinely loved his mother and was devastated by her execution, which made him even more bitter towards the surface world and he has resented Arthur for the death of Atlanna ever since, taking the time to blame him for their mother's death, which while partially to manipulate Arthur into challenging Orm, was also done because Orm genuinely believed Arthur caused their mother's death, which succeeded in provoking Arthur, who angrily challenged Orm to a duel, but even then, Arthur couldn't help but feel sympathy for Orm's pain over the loss of their mother, which led to him refusing to strike down Orm later on. The fact that his mother was still alive and Arthur had rescued her was enough for Orm to accept his fate, surrender and be imprisoned for his crimes, despite the fact that all he did was for the greater good of his people and his initial demands of Arthur killing him. Although he despised Arthur for the fact his birth caused Atlanna to be sentenced to the Trench, Orm seemed to have a level of kinship for his half-brother, stating that he did not want to kill Arthur and giving him several chances to leave forever. He also looked shocked, regretful and even a bit grieving when he saw Mera's ship sinking in lava, thus believing she and Arthur are both dead. Although he does not answer when Arthur suggests they have a brotherly talk later on, he seemed to contemplate doing so as he was taken away to be jailed. His relationship with his father was not well-known, but it seemed Orm highly respected his father's fighting skills, describing Orvax as having been unchallenged during his reign and his trident never suffering defeat and even stating Atlanna's trident was flawed, although he still showed some respect for his mother's fighting skills by stating that her trident was nevertheless powerful. Orm also appeared to respect his teacher Nuidis Vulko, as he clearly sounded betrayed as he revealed to Vulko he knew of his treachery and asked his mentor why, appearing to be somewhat jealous of how Arthur was favored by Vulko and asking that he at least be given a view in his prison.
Powers and Abilities
Atlantean Physiology: As a high-born Atlantean, Orm possesses incredible superhuman abilities that surpass most other Atlanteans, with only other high-borns, such as his mother, Nuidis Vulko and half-brother currently being his equal in power. As a warrior prince of Atlantis, Orm was trained in the battle arts he has practiced for years to become the best.
- Superhuman Strength: Orm naturally has incredible strength as a high-born Atlantean, making him far stronger than regular Atlanteans. He was strong enough to swiftly cut through the metal of a submarine with his trident, as well as raise a huge pillar to save King Nereus when he was caught during the attack on the Council of Kings. Orm's strength allowed him to greatly rival and even at certain occasions surpass Arthur in combat, with him repeatedly able to send Arthur flying a great distance, causing him pain, with his blows and even able to throw him to the ground and break his trident with several blows in their first fight as well as hold Arthur to a standstill when they struggled with their tridents clashing, eventually able to force him off, and still knock him around with his blows, only being outdone when Arthur used Atlantis's ultimate combat technique to force him back and leave him stunned long enough to break his trident. He was also able to quickly kill the Fisherman King, defeated the Brine King, and several Trench monsters with relative ease. Orm's strength also extends to his ability to jump great distances.
- Superhuman Durability: Orm possesses nigh-invulnerability, including resistance to explosions of powerful energy, immense blunt-force trauma, falls from great heights, explosions, low-caliber bullets and tremendous underwater pressures. Additionally, he endured many extremely powerful blows from his half-brother Arthur, as well as Mera's hydrokinetic attacks. However, Orm is seemingly not immune to molten lava, as he made an effort not to fall into it while fighting his half-brother.
- Superhuman Speed: While underwater, Orm can swim at supersonic speeds. Orm's speed was able to rival and even, at times, overcome his brother Arthur, dodging many of his brother's blows with relative ease.
- Superhuman Senses: As an Atlantean, Orm possesses enhanced senses to help him better navigate underwater.
- Amphibious Adaptation: As a high-born Atlantean, Orm can survive both on land and in underwater environments, unlike most Atlanteans, who cannot breath air.
- Aquatic Respiration: Orm can naturally breathe underwater.
- Master Combatant: Having trained his entire life at Atlantis to become the best, Orm is extremely skilled in both armed and unarmed combat, being an 8th Dan Nautilus in Xebel-Fu and the five-time undefeated trident champion. He was particularly adept at fighting underwater but also considerably skilled in fighting in a surface environment, as shown by how he was able to dominate his half-brother Arthur throughout the majority of their first fight, which took place underwater, and eventually come out on top, only being prevented from killing Arthur by Mera's interference and in their final duel, which took place on land, Orm was still able to stand toe-to-toe with Arthur, forcing Arthur to use Atlantis's ultimate combat technique, which Orm was unprepared for, to win. Moreover, Orm swiftly killed the Fisherman King, defeated the Brine King quickly, and even slayed many Trench monsters with relative ease.
- Trident Mastery: Being the five-time undefeated trident champion, Orm is extremely skilled in the use of his trident in combat. He used it to cut a submarine, kill the Fisherman King, as well as quickly overpower the Brine King and slay many Trench monsters. He was able to match his brother Aquaman's use of their tridents, even besting and breaking their mother's trident in their first fight and forcing Arthur to use Atlantis's most powerful polearm technique with his newly acquired Trident of Atlan to emerge victorious in their final fight.
- Master Swimmer: Orm, like all Atlanteans, is an extremely skilled swimmer.
- Expert Leader: Orm is a very capable leader, with the people of Atlantis following him without question, only accepting Aquaman as their rightful king after the latter acquired Atlan's trident.
- Expert Pilot: While pursuing Mera and Arthur, Orm was able to easily pilot an Atlantean warship.
- Expert Rider: Orm, due to regularly battling from the back of his massive tylosaur mount, is an extremely skilled rider.
- Ocean Master's Suit: Orm wore this armor during the Battle of the Brine and his second fight with Aquaman. The suit is highly durable. Its helmet withstood repeated strikes from a massive propeller with no sign of damage. The face area also changes to reflect Orm's expressions.
- Trident: Orm wields his father's trident as his main weapon of choice. It is made out of Atlantean steel, being able to tear through a submarine and break Atlanna's trident with a couple of strikes. It was, however, destroyed by Aquaman using the Trident of Atlan.
- Orm's Golden Armor: Orm wore this armor upon first meeting his half-brother, Aquaman in his throne room.
- Orm's Gladiator Armor: Orm wore this gladiatorial armor during his first fight with Aquaman in the Ring of Fire.
- In the DC Comics universe, originally Orm was Aquaman's human half-brother and was the son of Thomas Curry and a woman named Mary O'Sullivan. He resented the fact that he had none of Aquaman's powers, being fully human and eventually named himself the Ocean Master, a high-tech pirate who caused natural disasters in order to hold the world at ransom. In Post-Crisis, Orm is the son of Atlan and attempts to rise to the throne of Atlantis after having learnt his father was an Atlantean wizard. In the New 52, Orm is the half-brother of Aquaman, born to Aquaman's mother Atlanna and the warlord Orvax Marius. He again becomes Ocean Master, and an enemy of Justice League.