If your action didn't have the desired effect, check the darkness track!  These cards can reduce your damage, healing, courage gain, and more.  Stay on top of it with Prayer!

 Protect Saints!  They typically don't move, but protecting them will give XP and decrease the amount of Darkness coming at you.

 Be aware of which demons act next to prioritize what is a higher strategic value to smite.

 Being defeated is okay (as long as other angels survive)