Elathari's Blazing Ardor

You set alight the cinders of passion within all nearby enemies, turning them into a literal blaze that consumes your victims from within, exiting as flames through their mouth, ears and nostrils. Each creature with 5 or more Intelligence you choose within 30 feet of you must succeed on a Charisma saving throw or take 16d8 fire damage. Some types of undead and oozes in general are unaffected by this spell, due to lacking the neccessary emotions.

The DM can decide that certain other creatures are likewise unaffected by the spell.