Prismatic Engine

At the start of each of your turns, choose acid, cold, fire, lightning, or thunder. Hostile creatures in the emanation lose resistance to the chosen type and must make a DEX save, taking 27 (6d8) damage of that type on a failed save, or half as much on a success.

This power has its own stable page so it can be linked from any character, item, location, story post, bargain, curse, or future reward.