Ambient Fury

When a creature makes a melee attack against you (spells by touch count as well) you can use your reaction to release a blast of nacrotic energy throwing them sending them flying away from you. The creature makes a constitution saving throw; on a failure the creature takes 3d12 nacrotic damage and is thrown back 15 feet, on a successful save the creature takes half as much damage and is unmoved.

 When cast at a higher level increase the dice by 1d12