Even with explaining himself later on his mind, he still offers a shrug in the face of Zangetsu's grumbling. Then, it's on to what's important, right now, right here. Childermass looks around them, visually scanning for any familiar people still running around the ballroom.

"The Prince is retreating and changing this realm to suit his defense," he does explain that much, at least, since it's relevant. "But his resources are still scattered, which means so are his people, including the ones he stole from us. I don't need stealth, Zangetsu, I need someone who's fast and willing to punch out the people he's turned."

Specifically Tyki, sure, but if they have to punch some kids, well, so be it.