after your snooping around for Ace to find out wither or not Buttercup is hanging out with some of Fuse's monsters and finding a lair, Ace calls you back to hand you an all-access backstage pass that should let you get into the lair and find out once and for all if that is where Buttercup has been sneaking off to.
enter the lair. on entering the lair its found that, no it wasn't Buttercup that Lil Arturo saw but actually Fusion Buttercup. Ace then tells you to go and get rid of Fusion Buttercup while he goes off to pound Lil Arturo.
Defeat Fusion Buttercup
well Ace is relieved to finally know for sure that Buttercup hasn't been off to meet with fusion monsters and is still his girlfriend.
Omega Blacklight Pants lv14pants
2300 Fusion Matter