Ben 10 Season 7 Episode 1 Roundabout

Forever Knight finally assembles his Round Table of young but super-powerful Knights, including- Ben?! With his squires' help, Forever Knight turns a Particle Accelerator into a Time Machine and sets out to conquer all of history, but a certain hero with a team of 10 aliens on his side has other plans- foiling Forever Knight at every twist and turn in time- while Grandpa Max, Gwen, and Phil keep the rest of the Round Table busy in the present.