I know im gonna sound like a crazy mf but what if urouges final form is larger than his ship
So essentially urouge takes enough damage and he grows larger than his ship and he pulls off the 2 Naginata and the Hannya Mask from his figurehead
Urouge is 1 of only 2 ships with weapons on the front, the other one is the flying dutchman which is used by vander decken also someone who can those weapons, so why would urouge has 2 naginatas on his figurehead other than to use during his final transformation, also the hannya mask has good proportions to urouges face as well as wings flanking the hannya essentially saying the hannya is urouge