The small trace of doubt that Nezumi carried vanishes. This man can't read minds. A simple test could have proven his point. It's an easy guess that someone's next move would be to test this stranger's claims.

"Save your cheap parlor tricks for somebody gullible enough to buy them. I don't know if I even believe a knife couldn't kill you." But Shion wouldn't want him to, not without there being a defensive reason. Maybe not even then, but Nezumi will defend himself. "But I'll bet even if that's your one truth, they won't feel good. Enough cuts will make you wish you were dead."

He can't openly tell the man to stay away from Shion. That's opening a door to a weakness, even if he doesn't admit how big of a weakness Shion is for him.

"I dragged myself to this party, and I'll be very disappointed if I end up having to go home to change. Even if you look like that, try to keep from trying anything."