Ben 10: Alien Force (2008)

S2E8 Voided

When Gwen gets an urgent distress signal from Helen, Ben is compelled to venture into the Null Void to rescue her and Manny. Upon his arrival, he realizes he needs to locate The Wrench to confront D'Void, who, as fate would have it, is none other than Ben's former foe, Dr. Animo.