Eon

Eon is a time-travelling villain and an alternative version of Ben Tennyson, the main protagonist in the Ben 10 series. He is the main antagonist in Ben 10: Race Against Time. He differs in the different series he appears in; in Ben 10: Race Against Time, he appears as a humanoid alien from the planet Chronia, in Ben 10: Ultimate Alien he looks like Ben 10,000 and in Ben 10: Omniverse he is a human with time-based powers.

Ben 10: Race Against Time
He first appears when he starts blasting energy at objects in the town, Bellwood. Later, when Heatblast appears and then the police appear. Heatblast stops Eon's Servants and later seemingly defeats Eon.

Later, Eon appears at a clock tower. When Eon gets a headache, one of his servants try to help him but he kills it with an energy blast revealing its face. Eon informs the rest of his servants to "let him die", as they are here to serve him, not each other and threatens them to put them back in their cold cages. Eon views his home planet and the ships of the fleet of his race who are trapped outside of time and space. He says that nothing shall thwart him once Ben Tennyson is dead.

Eon appears in an image that Gwen Tennyson has taken. When Max Tennyson appears he tells Ben and Gwen about Eon. Later, Ben, Gwen and Max Tennyson meet up with a plumber who was in charge of Eon, Constantine Jacobs that was aged by Eon to the point that he was old in the blink of an eye. After the plumber finishes explaining about Eon, he dies.

Eon later appears, trying to activate the Hands of Armageddon but he's to old to do so. When Eon sees Ben Tennyson, he malfunctions his Omnitrix. Ben Tennyson tries to get away but Eon gets him cornered. Eon is stopped by an old plumber.

Later, Eon appears at the hall of Ben's school. Ben fights Eon as Diamondhead. Eon reminds Ben that when an alarm sounds, the entire school gathers to the hall. Eon teleports away and Ben hides.

Eon appears with Ben, Gwen and Max, chained, after being kidnapped by his servants. Eon tells Ben, Gwen and Max about his race, planet, the Hands of Armageddon, the Omnitrix and he also tells Ben that he is him. Eon turns Ben into a younger version of himself and teleports away as two cannot exist in one world.

Later, the real Eon appears and stops time, except from Ben. When he throws Ben, Ben turns into Wildmutt and fights him. Eon is whacked into the Hands of Armageddon by Wildmutt using frozen Gwen, defeating Eon.

Ultimate Alien
To be added

Omniverse
To be added