I know it wasn't a race, that was just the name of his particular daemon. Sorry if I didn't make that clear. Also I remembered that half way through making the CS but then I'm just planning on rolling with it. Basically, his religion is about decay, rot, misery, and disease right? So I'm going to have him and his followers build houses, destroy houses, and cure the sick.

By building houses they are killing trees, by destroying houses they are contributing to the decay of things, and by curing the sick they are prolonging that creatures suffering. Since this is modern times, they can't go around spreading death and disease actively by slinging spells and destroying stuff, so they must do it passively.