yea, i think that Hades brainwashes Hercules (or turns him into a heartless) and then commands Herc to eliminate Auron!!!!
or it could be:
Hades summons Auron and tells him to eliminate Herc. Auron gets a beating from Herc and Herc breaks Auron's hand. Hades then summons Auron again and tells him to eliminate Sora, but Auron says enuff is enuff!!!! good huh?