Weapon XI: Part 1 is the fifty-ninth episode of Ben 10: Omniverse.
The episode start on the Albright farm, where Alan can be seen entering to their warehouse. He goes in, turns into his Pyronite form, lights up a candle and turns back. He begins working on his car when suddenly the doors open. He stands up and sees Kevin Levin who greets him nicely along with Argit and Zed. Alan reminds him that he drained his powers last time he showed up. He tells them to get out of his property but Kevin wants give his memories back, however, Alan thinks he wants to attack him. Argit tells him that he is not in danger but suddenly Swift appears by breaking the roof and spots on Alan. They begin to fight...
- Servantis turns the Amalgam kids evil, and convinces Kevin to join the Rooters.
- Servantis explains that he made Kevin closer to Ben to destroy him.
- Ben was the coming storm Servantis was talking about.
- Ben Tennyson
- Rook Blonko
- Gwen Tennyson
- Kevin Levin (present and flashback; villain at the end)
- Amalgam Kids
- Gorvan (cameo)
- Alan's donor (flashback)
Kevin: Hunt them down. Hunt them down, and destroy Ben Tennyson!
- Feedback is missing the golden battery bolts on his shoulders, arms and hips, when Ben uses him.
- During Alan's Flashback part of Servantis' head coloring matched his face coloring at the beginning.
- The title of the episode is a clear reference to Weapon X, the code name used by Wolverine, the mutant superhero and member of the X-Men, from Marvel Comics.
- The suit that Kevin wears at the end, is the same one Kevin 11,000 wore in Ken 10.
- It is revealed that Ben now has full control over Alien X since Universe Vs. Tennyson.