Aidka
Alan promised to release her family within a week if I remember right, and they are still waiting in prison. He's basically betrayed her on that point already so she has no reason to hesitate. It was made clear after the engagement broke that while she may blame Claus for her family's fall, the feelings she has for Alan are lukewarm at best; all she wants is her family freed. No chance she will join the harem though I would say; it's a bit too late in the game for that. Whereas the empress will be made to fall, Christine will likely just be placed to the side and ignored by Claus since he will have no real interest in her outside of the plan.