Well I don't think so. In Proud mode, if you lose against a boss battle, then a screen will popup saying I will not give up, or i am done.
Something like that. If you click, I will not give up, then Mickey Mouse will come make cream pie out of the boss (you get to control him, and he is much stronger than Sora). But you can't kill the boss with mickey. You have to heal Sora, then mickey leaves, and then you have to beat whatever life the boss has with Sora.
Mickey is really fun to play as though.
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