Insomnia Curse

Choose one creature within range. The target must make a WIS save. On a failed save, it cannot benefit from magical sleep, has disadvantage on saves against fear and madness, and the first time it finishes a rest during the duration it must repeat the save or gain no benefit from that rest.

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