Demon Gate was created by by Peter David. He first appears in his human form in Aquaman #4, after which he remains unseen until Aquaman #26 where he returns with his new cyborg body.
Kimon Tanaka was a sea captain who captured dolphins for a living for the Shinobi research center. Ultimately Aquaman and Lobo arrived with Lobo destroying his ship with a grenade leaving the captain floating, Aquaman then left his fate up to several sharks he had captured who mauled the captain.However he was saved by his brother the head of Japanese company Raiden Industries, who begins several experiments to save his life turning him into a cyborg.
Taking the name of Demon Gate he tracks down Aquaman's surrogate mother, the dolphin Porm through a tracking device brutally murdering her and branding the symbol of Raiden Industries to draw Aquaman to him. Aquaman and Dolphin then confront the founder of the company, only for Demon Gate to show up and reveal his origin and his part as Porm's murderer. Aquaman and Demon Gate then enter into a lengthy battle which runs throughout most of the building, until he is ultimately knocked from the building crashing many stories to the ground below, with Aquaman preparing to kill him only to be interrupted by the police. Ultimately Aquaman seeks to have Demon Gate turned over to him so that he may face justice,but is denied this by the Japanese goverment spurring Aquaman to ban the people from the oceans and a 24 hour notice to turn him over or face war.
Shortly after Aquaman piloting Poseidonis above Tokyo's streets, Demon Gate's brother turns off his body turning him over to Aquaman who takes him to the royal palace and places him on trial. However his life is ultimately spared and Dolphins,Nemek and all fish life around, Aquaman then commutes his sentence to life on a empty island with none of his weapons. And his only food to be seaweed and dead fish brought to him by the local sea life to show their unparalleled mercy.
Powers and Abilities
Demon Gate was a skilled sea captain and illegal dolphin hunter and after his transformation became a very dangerous cybernetic adversary.
Skilled Hunter / Captain
He was a very skilled hunter and captain of a number of boats.
Weapons and Equipment
His transformation to a cyborg provides him with superhuman strength and durability. He can fight Aquaman for a while and survive a drop from the top of skyscraper. He can also breath underwater via his suit. He can also track beacons through his suit and has enhanced vision.
He uses a remote controlled spear that can be charged with energy.
Wrist Mounted Flame Thrower
His suit includes a wrist mounted flame thrower