The sea-faring member of Earth-3's Crime Syndicate, the Sea King exists as the villainous counterpoint to Aquaman.
Sea King was created by Geoff Johns and Ivan Reis. His first appearance was in Justice League #23 (October 2013).
Major Story Arcs
Justice League: Trinity War
The Sea King was the first member of the Crime Syndicate to arrive on the Earth of the main DC Universe, following the Outsider's opening of Pandora's Box. Due to the strain of interdimensional travel, he perished upon arrival.
Justice League Dark
The Sea King reappears in Justice League Dark, with no memories of his past. Filled with an uncontrollable rage, he finds himself up against John Constantine, Swamp Thing, and Nightmare Nurse. Attempting to swallow them within an ocean wave powered by the spirits of Nan Madol, Sea King is dropped by a mystical severing spell. It is revealed that Justice League Dark member Deadman had jumped into Sea King's deceased corpse after the Syndicate's assault. Due to the King's echoing traces of evil, Deadman lost control of the body and fell prey to an amnesiac state.
Using his magicks, John Constantine has cleared out all remnants of the Sea King's psyche, but has also trapped Deadman within the King's body as part of his endgame against Blight.
Powers and Abilities
Sea King has shown some of his powers and abilities in combat against Justice League Dark and Blight, displaying some similarities with Aquaman and normal Atlanteans as well as some other more exotic powers.
Sea King has been shown as strong enough to casually toss Pandora across the ancient underwater city Nan Madol with one hand. The extent of his super strength is unknown.
Sea King has been shown as durable enough to withstand a direct strike from his Trident to the chest and continue fighting seemingly unaffected and direct strikes from Blight (in addition to the standard Atlantean resistance to deep sea pressure and temperature extremes). He was also able to survive without much trouble a direct clash with Nanda Parbat's mystical shields. His death at the end of Trinity War has not been explained but it's suggested during Forever Evil that he was killed from the force that drove the Crime Syndicate away from Earth 3.
He can function normally underwater and is able to withstand the high pressures and extreme temperatures of the deep, like Earth 1 Atlanteans. He can also move very fast underwater, being able to surprise and slice through Swamp Thing before he could react.
Enhanced Speed / Jump
Sea King has shown the ability to move faster than humans on land, blitzing an entire squad of demons in Nanda Parbat, as well as a superhuman leaping ability (similar to Aquaman), both while leaping out of water or on land.
Sea King has shown the ability to see normally even at the bottom of the ocean.
Magic (Water Control and Energy Blasts)
Sea King has shown the ability to channel and control magic through his Trident, which allows him to control water on a massive scale and fire extremely powerful blasts (strong enough to sink a huge ocean faring ship in a single blast).
Skilled Warrior / Leader
Sea King seems to be skilled in combat, particularly with his Trident and his Harpoon hand (which seems to have replaced his left arm) as he was able to hold his own against Justice League Dark. He is also seen leading the spirits of Nan Madol into combat and taking out a big squad of Nanda Parbat's guardian demons on his own.
Weapons and Equipment
The Sea King wields a magical Trident and his left arm has been replaced by an implant in the shape of a Harpoon (similar to the one Aquaman had during the 90's). Both items seem to be forged by the same material.
Sea King's Trident
Sea King wields a magical Trident that has the ability to channel magic for various effects such as magical blasts and water control.
Sea King's Harpoon Hand
Sea King's left arm has been replaced with a Harpoon-like implant. The Harpoon is strong enough to slice Swamp Thing in half, in one strike.