"You're welcome, though as I said, I don't know how much help I'll be."

As for his other statement... What to say to something like that? Fighting was usually more of an abstract or an occupational hazard, not something people would casually mention before marching out to face literal nightmare monsters.

In the rain.

Something about the rain makes it worse.

"... Good luck," she offers, somewhat awkwardly, really unsure what else there is to say. "Stay safe."