Ben 10: Omniverse S07 E09 It's a Mad, Mad, Mad Ben World (1)

"Two Bens are better than one."

A dangerous Chronosapien named Maltruant attempts to obtain total control over the time-space continuum with the help of an old relic called the Key to Time; Ben 23 is sent by the Azmuth of his dimension to Ben Tennyson's dimension in order for the latter to act as a "mentor" to the former.