Ben Ten: Enter the Ultimatrix

Ben Ten: Enter the Ultimatrix is a series based off a theoretical end of Omniverse where Dagon returns and unites Ben's greatest enemies, so Asmuth creates another Ultimatrix on Ben's request. This series brings back Gwen and Kevin as major characters, and adds Nolan, a human (sort of) that sheds his skin, and the Doctor, the last Time Lord, being from Ashtown Burials books and Doctor Who respectively. The Rustbucket, Proto-TRUK (reassembled from the Time Bikes with some new upgrades), Ten-Speed, and TARDIS have all merged into one vehicle, and they have an entire huge team: Ben, Gwen, Kevin, Rook, Grandpa Max, Nolan, Paradox, the Doctor, Amy, Rory, Clara, Rose, the Plumbers' Helpers, Rad Dudesman, and Hobble! Ben can ultimize all his forms, and new aliens include Commoncold, Gemini, Sandbox, Joker, Sontar10, I AM THAT IS, Icebox, and Assasin10. The theme song (to the tune of season 1 Omniverse):

Ben Ten, he's a kid with a watch on his arm', 'Which lets him change shape and save Earth from harm,

(shows the Omniverse first-verse scenes, but Gemini strikes a pose, Jetray flys, and Commoncold jumps from a purple cloud)

Ben Ten, he finds the trouble when it's taking place, And then he stares evil in the face,

(shows Sontar10 slamming his fists together and green light coming out, shrinking into an Ultimatrix symbol, then zooms out to see it's on Ultimate Gravattack's forehead)