The problem with rain is that 80% of the fire in this game is necrofire that can't be doused. Honestly my token mage only has it on the bars to set up freezes now, it's way unreliable and way too easy to ignore vs fire-spammers.
I wish you could bless the rain to douse necrofire. It's such a nuisance ability that takes way too much to get rid of, given how most enemies able to produce necrfire can just continue spamming it the turn after you doused it -- making you wonder why you bothered.