Dream Eater

You target a sleeping creature's dreams and sap the power existing in their dreams. 
The target must succeed on a Wisdom Saving throw or take 2d10 psychic damage and the caster heals an amount of HP equal to the spell slot level or half as much on a successful save and the caster recovers no HP. 

At higher levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d10 for each slot level above 1st.