[Marco gets that look on his face that adults get sometimes when they have to explain something complicated to a kid, like why their goldfish is swimming belly-up, or why the good guys didn't win in Titanic.]

He's not... trying to kill monsters, exactly... [He wrings his hands.] Not deliberately. But... monsters have a lot of the Fog God's power in them, see, and that's the problem. Driving it out might turn out a little painful. For that reason.

B-But it's going to be fine once it's all over. [He tries a smile. It's not the most enthusiastic one.] Everyone is going to be safe.