This wasn't the cyborg Vilgax of the past; this was a "Conqueror of Ten Worlds" with a vast array of powers, including flight, super strength, and wind breath, making him a more versatile threat than ever before.
Because Diamondhead is composed of nearly indestructible organic crystals, he is the perfect counter to Vilgax’s brute force. Ben manages to defeat Vilgax, forcing the conqueror to retreat and sparing the Earth. Why This Episode Matters [S3E2] Vengeance of Vilgax: Pt.2
Instead of unlocking Master Control, the Omnitrix resets, and several of Ben’s alien forms (including Chromastone, Goop, Way Big, and Spider-Monkey) are physically ejected from the watch as independent, mindless entities. This wasn't the cyborg Vilgax of the past;
This episode signaled a darker, more consequence-heavy tone for Season 3. Ben’s arrogance in trying to hack the watch led to Kevin’s mutation, a burden Ben carries for a long time. Why This Episode Matters Instead of unlocking Master
Ben enlists Kevin’s help to break the Omnitrix’s physical seal. The experiment backfires spectacularly: