SooooooooOoo since Gui is a mimic-siren thing, he gyat to have gills soo the things on his neck are gills ^^ Not anything else. He also has lungs, so if they get clogged he can still breathe. Yes, he can breathe underwater.
I luv me pwetty boi who loves boys. (He's Pans3×ua1 dontcha worry simps...)
