[1] While the character is depicted as the half-brother and one of the most enduring and recognized adversaries of Aquaman,[2] Ocean Master has been subjected to numerous revisions to his origin stories throughout his history.

Unlike other past portrayals, the character is inherently less malicious[5] and his relationship is more complicated with Aquaman as he weighs their rivalry with protecting Atlantis, making him a supervillain and akin to an antihero at times.

Ocean Master first appeared in Aquaman #29 (September 1966), created by Bob Haney and Nick Cardy during the Silver Age of Comics Books.

[7] He grew up under the shadow of his heroic half-brother and resented the fact that he had none of Aquaman's powers, being fully human, and he was already a petty criminal when he was stricken with amnesia and forgot all about his former life, disappearing shortly afterwards.

[volume & issue needed] Several years later, the self-named Orm Marius reappeared as the Ocean Master, a high-tech pirate who initially attacked ships but quickly moved on to causing natural disasters to hold the world at ransom.

[8] In the earliest chronologically depicted story from Ocean Master's youth, Aquaman encounters a young Inupiat woman whom he rescues from a polar bear attack.

[8] Ocean Master clashed with the JLA again when he attempted to claim the remains of Atlantis following Aquaman's apparent death in the 2001 storyline "Our Worlds At War".

Unlike previous depictions of the character, Orm is cast as a full-blooded Atlantean and is initially characterized as having genuinely, brotherly love for Arthur and holds disdain towards "surface dwellers" for their acts that have polluted the oceans for thousands of years and prefers not sharing the Earth with them.

Despite inclinations to attack the "surface dwellers" for perceived crimes towards the ocean, Orm instead ruled for the benefit of his people and adhered to a code of conduct.

[19] While Orm and his Atlantean soldiers plant bombs in an attempt to sink the city and face off against the superheroes that Cyborg called in as reserves, they are attacked by a race of sea creatures known as the Trench.

[21] Afterwards, the renegade Atlantean, Murk, makes plans to break Orm - now known by the media as the "Ocean Master" (a name he despises) - out of Belle Reve.

A diner employee named Erin desperately pleads with Orm to save her young son Tommy, but he refuses, instead heading back to the ocean.

[27] Eventually, Ocean Master re-emerges with a new status quo; now depicted as a reformed super-villain having given up his former life to live on dry land with Erin and Tommy, he is conflicted between the safety of Atlantis and his envious-driven yearning to overthrow his rival and brother, Aquaman.

At the start of the series, he is shown to be engaged to Erin and views Tommy as his son, having decided to leave Arthur to rule Atlantis and settle down with his new family.

However, when he learns that his brother has been deposed by the usurper Courm Rath and is now presumed dead, Orm silently leaves Erin and Tommy in the middle of the night, feeling duty bound to reassert his claim to the throne.

In the "Drowned Earth" crossover event, when all the inhabitants of Atlantis besides the two of them are transformed into monsters by tainted waters released by a trio of alien sea gods.

Following Drowned Earth, Orm hid as a beggar on the streets of the Ninth Tride, Atlantis' poorest district and closest to the sea floor.

Orm would go back to slay the Marine Maruder for her transgressions against the Atlantean she abducted and fed her body to his newfound followers, christening them citizens of the "City of Dagon".

Due to his choices in choosing his life as Ocean Master and Atlantis over them, Erin breaks up with Orm though he relents that despite all matters, he considered Tommy his son and will approach him when he is older and give him the option of being his heir before leaving her.

Now backed by Atlantean outcasts from the homeless population of the Ninth Tride and the Lernaea from loyalty, Orm officially christens himself king of Dagon.

[30] Months following the royal birth of Princess Andy, Orm began undermining Mera and her council's rule using his status as king of Dagon with the intent of establishing Dagon a new city-state capital by ushering in several tactical gambits; he manipulates the poorer populace of the Ninth Tride in his growing army, begins winning support from other kingdoms, and manipulates his brother by having Lernaea abduct Andy and hidden away to expose the more dangerous and terrifying side of his brother's personality to stow the question of having a possible ruler who can be considered easily provoked.

The battle is interrupted by Dolphin and Orm's second-in-command, Pilot, in which both exposes him as the mastermind behind Andy's kidnapping and his intent in using the Dagoian forces he cultivated in a bid for power.

When the original timeline is later restored, Ocean Master is once more Aquaman's enemy and their shared mother, Atlanna, is revealed to have passed away (having done so between the Maelstrom storyline and series).

[33] During Geoff Johns's run on Aquaman, the character received a love interest in the form of Erin Shaw, a human woman native to Florida whom he saves alongside her son during the events of Forever Evil despite his typical characterization in his aversion and xenophobic views of the "surface world".

[25][26] The two later break their engagement due to Orm's priortization of his homeland over Erin and Tommy, believing that his royal duties calls for sacrificing what he desires most.

The helmet featured gill functionality, enabling him to survive underwater for extended periods and endure the intense pressures of the ocean depths.

[36] Following the events of Crisis on Infinite Earths, It was revealed that Ocean Master, being a descendant of ancient Atlanteans, possessed a hybrid nature that granted him mystical potential.

[35][34] This granted him a range of abilities, including superhuman strength, the capability to breathe underwater indefinitely, teleportation, illusion casting, and the power to summon magical creatures from the depths of the ocean to aid him.

[40] This particular classification is shared by numerous other superpowered metahumans in the DC Universe, including Black Adam,[41] Green Lantern, Mary Marvel, and various others.

The current version, due to his Atlantean biology, dehydrates at an accelerated rate compared to humans, gradually making him weaker when spending prolonged periods on the surface without regular hydration.