Hiyori should've been the one thrown with the scabbards and Momo should've been in the past to be trained to fight with the scabbards to bring down Kaido/his crew. Momo will probably somehow be the one which diverts Onigashima from falling on the capital. That makes the most sense. I hope we get a flashback to see what specifically happen. I feel like Luffy wasn't actually "beat" by Kaido, but rather he is KO'd from overuse of Haki. He didn't seem to really be more damaged than we last saw. That could be interesting.