The heaviest story in the franchise. Kevin has become a monster. Ben tries to kill him. Grandpa Max orders Ben to stop. This two-parter asks whether heroes are allowed to be executioners. It remains controversial among fans.
As of 2025, Ben 10: Ultimate Alien all episodes are available on:
You can also find the complete DVD box set titled "Ben 10: Ultimate Alien – The Complete Series."
The 52 episodes are generally structured around three major narrative arcs: