I keep telling myself that. KH2 was a weird 3-sided battle. I mean, everyone (heartless, sora and gang, and maleficent/pete, etc) was against Organization XIII so it was natural for Maleficent and Pete to be that way. But I wonder..... they seemed to be of much help to Sora and gang in the storyline, yet Maleficent still wants revenge against Sora?
There's a similar situation in Full Metal Alchemist.