You don't fight the enchanted objects. Here's the story of B&tB's world by what's been confirmed so far:
Sora, Donald, and Goofy get to the castle to find that all the castle staff has been put in the dungeon by Beast. You fight heartless until you get to Belle's room. The dresser, the only enchanted object not imprisoned (how convenient) fills you in and tells you what to do from there. There's a lot more to it, but I forgot it

. We don't know why Beast has gone mad and imprisoned everyone, but it has something to do with an unknown who's brainwashing him. For those of you who don't know, and unknown is a creature in a black coat who does not have a heart. Beast even attacks Sora and the gang because he doesn't remember them. They get thorugh to him though, and he joins your team and you go on to fight the boss. I'm sorry, I can't post images. I've tried and tried, but it either doesn't work or I get the box with an "X" in it.
Oh, and the boss is not Gaston, but a creature that kinda fuses with a room in the castle. I don't know how to explain it; I really with I could get the hang of posting pictures so I could show you.