"That's... hard to tell. The prevailing theory is that if Faust wins, he could win political favour with her by being the one that aided her victory by bringing the Bloodfeathers into her forces. However, he also gains by removing opposition to his claim to the throne should the Emperor's son die fighting. There's also the small possibility that he hoped Faust and the Bloodfeathers would be enough of a distraction to make his move for the throne."