Ben 10 Omniverse: S01E01 The More Things Change Part 1. Flashback

This entry in Cartoon Network's popular `Ben 10' franchise features the superhero exploring the quirky side of the alien underworld in a secret alien city. Although Ben's ready to work alone, Grandpa Max teams him with a new, by-the-book partner. Along the way, Ben discovers enemies from his past looking for a rematch as well as a new batch of aliens to battle. While Ben is busy dealing with the aliens, a mysterious hunter is hot on his trail.