Yeah, that fight is insanity. What I would recommend is just wander around the area right after Bowser's dream, and bash up baddies. Don't forget the EXP boost badge combo.
Oh, that. Well, in that, you really have to learn how to not get hit. Is there a specific part that's giving you trouble?
@Sven Svennson. Vs Pillodium was the first time I almost game overed. It took half the fight for me to figure out how to counter its hammer. And even after beating it I never managed to dodge its lasers