Chronians are a time controling alien species from the destroyed planet
Chronia. Chronia was once beautiful, until it was destroyed by an unknown reason. The Chronians were homeless, until an army led by tthe Chronian known only as
Eon. He and his army were going to try to use the
Hands of Armageddon to begin an invasion on Earth by the Chronians. Then they would not be homeless anymore. Ben Tennyson try to stop him, and Eon knew he was too weak to activate the Hands of Armageddon, as time travel disorientates Chronians. Eon programmed his Chronian DNA in Ben's Omnitrix to overwhelm Ben so Ben could activate the Hands, because he was now a stronger version of Eon. He activated it, and Chronian ships began to come to Earth, but Gwen reached into Eon's body and saved Ben from it. Then he and Grandpa Max shut off the hands. At the end Eon attacked Ben, but Ben turned into
Wildmutt and threw Eon into the Hands of Armageddon. It is unknown what became of the Chronians. These events happened in the movie "
Ben 10: Race Against Time".