He appears out of nowhere. Possibly identifies himself as the sword that cleaves evil. Yells Chesto while cutting something in half. Claims there is nothing that can stand before his Zankantou.
What's awesome about this scene is that the Shadow-Mirror guys are basically all going "relax, it's only one unit, persue and destroy", and then Sanger shows up and suddenly they're all "Holy FUCK, throw EVERYTHING we have at this guy RIGHT NOW!" Which is the appropriate reaction, really.
Lesson in this vid: When you see a BFS suddenly pop out of nowhere in the middle of the ocean, you don't just stand there and stare at it like a brainless lizard. You f**king run...