Sanji thinks he's got Zoro's number from day one, and there's not a thing about the swordsman that doesn't look monstrous. Then Sanji runs into the Vinsmokes again and is reminded what real monsters are like.

there is blood under his fingernails and all of it is his; he doesn't clean it out, just looks at the dark lines while the water runs, thinks about the scrape of his nails over stone while he writhed at joker's feet, tearing the skin from his fingers, unfeeling in the face of other agony.

If he lives you’ll kill him yourself, for being so recklessly good-hearted, for being such a fool.