Board Thread:Questions and Answers/@comment-33563508-20180212142147/@comment-32133544-20181002091653

Highbreeds are not much stronger, as they were defeated by the aliens such as Humungousaur, Swampfire or Echo Echo.

Vilgax(AF) was defeated easily by Way Big or Diamondhead.

Ultimate Aggregor was defeated by Mutated Kevin, Ben was not able to defeat him.

So, of course: Ultimate Aggregor would win.