rofl, I only started farming and gathering Phozons after that fight, and I was glad too, because the game got progressively harder (like the gaywizard and Belial fights etc). Mercedes was fucking amazingly broken when you play her right, especially with high magic (can't remember the name) level.

Though the way I beat Oswald was pretty satisfying, I farmed up a bunch of painkillers, Ice Spirits and Unlimited power potions, used them all together and raped him. Actually I did that for mostly all of Mercedes' bosses.

Oddly enough, for a character that looks like her she is surprising unannoying, and for the way Violet looked, she was surprising annoying.