Nightmarish

This action is. It's also Aggressive, meaning it is affected by 's and 's. The victim's regular sleep message will be different, but they will not know who cursed them. The effect lasts until the victim gets up; after that, they can sleep normally (if they lay down again).

Fairly useless or highly situational, as the Covert quality means it cannot be used on characters in the Dorms, which will be under surveillance, and giving nightmares to single characters in the Medlab will make it obvious that you caused them.

New action

 * Privacy:
 * Target: Lying down character
 * Effect: Cancels the target's resting bonus and replaces their sleep message until they stand up again.
 * This action is Aggressive.
 * Room Log: [Mush] approached [target]... After moving away again, the latter seems to sleep really badly.