Is Grey Matter the worst alien in the Omnitrix?

There is an updated Grey Matter, Ultimate Grey Matter and I think he is probably deadly. When you are up against a super brain not just about super muscles or physical powers you know that no plan you can adopt is going to be a match for the greater planning ability of a super mind.

Omni-Enhanced Grey Matter is the Upgraded Omnitrix's Omni-Enhanced version of Grey Matter. Omni-Enhanced Grey Matter looks like regular Grey Matter but he's inside a large stone that protects and operates similar to a mecha suit.