Just a nightmare

The dreameater only attacks sleeping targets and a battle against the dream eater does not take place in the physical world, but in a dreamscape created by it. A creature that is ‘killed’ by the dreameater does not die. Instead, they do not gain the normal benefits of resting and their mana is reduced by 2. If their mana would go below 0 because of this, they instead lose 5 Max HP per mana that could not be reduced. This effect lasts until the creature completes a rest undisturbed by the dreameater or until the dreameater dies.