Ben 10: Ultimate Omnitrix 2 (the Movie)
This is a movie between Season 4 Finale and Season 5 opening. This two hour long movie also has the enhanced Season 5 opening with Eye Guy, Fourarms, Stinkfly, Ghostfreak, Spitter, Buzzshock, Upgrade and Wildvine included.
The League of Ben's Enemies has conquered earth. Psyphon and Vreedle Brothers attacked Bellwood with an army of Stone Creatures made by Hex and Charmcaster. Ben slaps the Ultratrix. However, Ultratrix is in a dormant mode. So, Paradox asked Ben if he get a last chance to save the Universe. Ben agreeds so Paradox rewinds the time. So Julie and ship arrives telling Ben that Paradox sent them. Max gives directions of where to go, to Planet Lunareptilia, the homeplanet of Gooey. Ben has to find an Sub Energy core on the planet. He meets Zombozo who fights him. He defeats him as the Ultratrix awakens from the Dormant Mode as Fourarms. He realized Zombozo had taken the Sub-energy core. Julie explains that Zombozo took it to Planet Intellecto, Cerebellum's homeplanet.
On Intellecto, Ben finds it pretty foggy. So, Ben uses Swampflame, to light the way. Gwen and Kevin gets captured by Albedo who is working the sub energy. Ben fights him and puts him in the Null Void. The sub-energy core wasn't the only one. Ben must go to MorOtesi, the planet of Chromastone.
Ben finds that Charmcaster has clouded the planet by a mystical fog. So, with the help of Verdona Tennyson, he was able to get the temple, where the sub-energy is used to be worshipped. Charmcaster uses trap-doors to escape but Ben was able to find her as Ghostfreak.
After finding two sub-energy cores, Ben returns to Earth where Vreedle Brothers, Psyphon, Zs'Skayr, Rojo, Vulkanus, Circus Freaks and Aggregor are waiting for him. He finishes but project the sub-energy as Null Void projector using Cerebellum. Vilgax and his robots duels Ben. Gwen and Sunder duels. Azmuth helps Ben unlock, one of the most physically powerful alien, Doomsday. Ben defeats Vilgax and returns to original timeline.