Acnologia makes his return here to take on Rei. Rei has some pretty interesting abilities of her own including a powerful transformation/summon. Her tears have more power than most but even so that won’t be enough to shake Acnologia. He was able to wipe whole islands off the map with a single blast. Rei has never displayed such a level of ability and would just really be out of luck here. I don’t think there’s a whole lot that she could do to really stand up against such a fighter. Ultimately this is why she would have to take the loss. Acnologia wins.