Vengeance of Vilgax, Part 2

In the wake of the explosion, Ben discovers that several of his alien forms have been unleashed from the Omnitrix and are now roaming freely; additionally, Kevin has been irreversibly mutated into a mineral form. The team attempts to recover Ben’s lost alien forms (including Chromastone, Spidermonkey, and Goop), while Gwen and Kevin chastise Ben for his recklessness. The team attempts to track down Way Big, the last missing alien, but Ben runs out of time and is forced to face Vilgax. Vilgax nearly defeats Ben, but Gwen and Kevin arrive with Way Big, whom Ben absorbs back into the Omnitrix. However, Ben accidentally turns into Chromastone instead, and is destroyed by Vilgax. However, the Omnitrix absorbs Chromastone’s shattered pieces back into itself, transforming Ben into Diamondhead. Due to his skill and experience with Diamondhead, Ben easily defeats Vilgax, and he departs the planet in defeat.
Omnitrix alien debuts: Diamondhead