Try casting banish on the succubus, then Aura of Command on something else. Some people have run into a problem with Aura of Command causing a crash. Once it starts happening, I think the only current fix is to re-load a save where it still worked and hope it doesn't happen again. Hopefully the next patch will resolve this.
See;
Aura of Command bug - possible workaround.
Unfortunately, this was not a permenant fix
Aura of Command crash/freeze bug.
