Don-san loves his one-on-one humanoid combat encounters.In terms of scope, it's not as amazing as Wonderful 101 or Bayo 1's finaleplus the fact that a fusion of Sheba and Jubileus is summoned and you steer the final boss to its death is kind of a rehash (though it's still awesome regardless).
However, the actual fight itself feels closer to something like an Armstrong. It's an intense, personal fight compared to a giant, which I will always prefer. Had a lot of fun regardless, even with me dying constantly.
http://platinumgames.com/2009/10/16/on-creating-enemies/