I think I used Summoner form with familiars that spammed Tathlums with the special skill that improves it; that or Chrono Reaper Ex form and the time stop.
I got her with Magi form's ultimate. Didn't know they had ultimates because they aren't mapped onto the gamepad.
Kinda fuckin hate this game. Getting anywhere is a chore until you've got every room mapped to the teleport feather because of the horrid level design (the majority of the time I played this game I was lost with only a vague sense of where I want to get to and almost no idea of how to get there), all the big bosses require cheese and there's nowhere near enough yuri for a game that you spend 90ish % playing female transformations.
Cheese for two of the 5-star bosses in case anyone's interested:
Vega can be beaten easily by equipping a familiar with the knock-down command and berserk, probably just the knock down command even, stun-locks him so you can just sit still and fire charged magi-orbs.
The yellow one who eats your summons ( couldn't be arsed to remember the name ) can be cheesed by equipping a skill book as a familiar, it's immune to all damage so he can't eat it and gets stuck trying to, thus can't do anything else.
Playing on the release version, so if these don't work they've been patched.
