What would have happened if Fenrir's plan didn't work? If Antonin had ripped off the shirt covering her identity? It would have been a terrible scene. His absolute loyalty to her would've meant that the werewolf would likely have done what he could to prevent her capture. Who would have emerged from the bloodbath victorious was anyone's guess. Rabastan and Antonin were both formidable foes on their own. Together, they might have been unstoppable. Whatever the outcome, it was evident that at least one of them wouldn't have survived.