Ben 10: Ultimate Hero

Overview
Ben 10: Ultimate Hero is a series that takes place in an alternate timeline after the events of Alien Force.

Twilight:
'Ben is no longer able to use the Ultimatrix due to long term memory loss. The result is the destruction of the human race.'

http://ben10fanfiction.wikia.com/wiki/Twilight

Heroes

 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin
 * Grandpa Max

Villains

 * Vilgax
 * Ben Tennyson (Mirror Universe)