Endless Sea, often called Endless for short, is a rogue User who entered the OU with the technology to create plotholes and alter the fabric of reality. He is described as being a teenage boy wearing summer attire, who carries a backpack which is bigger on the inside. It is known to contain a laptop, a printer and some exploding nougats.
Endless's reasons for entering the OU and causing havoc with his technology inside remain unknown, but he had obviously been planning it from the User HQ for a long time, having already created some characters and given them independence so they could assist him with his plan once inside. An example is Ouandis, a Great Being, who he created with a gauntlet that could create plotholes, something which the normal Users would not approve of.
Shortly after arriving in the OU, he received a message from the Architect, who had been notified of his arrival and was wondering what he was doing. Endless replied with the notion that he was here to interfere and subsequently created the Five Empires Galaxy out of thin air. The Great Beings described this as a Class-W Reality Quake, which was felt by many, including Xigneo and Malygos. Next, he created a plothole which led to the concurrent fight between Maly, Ynot and Nadle to watch before summoning three of his characters to join in, Alaki, Alton and Togariku. The three battled the other three for a while before Endless summoned Gapyriad the Executor to finish the conflict. Before he could though, Endless decided to teleport himself and all his characters to the Eclipse Spiral, Ouandis's space station. Once there, Endless decided to have some more fun by creating a plothole underneath Vok and bringing him to them. However this turned out to be a very bad idea because once he'd made sense of his surroundings, Vok managed to destroy all their plothole creation and teleportation technology with his arsenal, escape to the docking bay, and steal the only ship there to fly back to Teruga Prime. Once in the ship he blasted the communications disk on the exterior of the space station and flew off, leaving the group completely and utterly trapped. With dwindling resources and no means of escape, Endless and his allies put themselves in stasis, to be awakened if or when someone arrives to rescue them.