Darkside

When you next hit a creature with a melee attack, add 4d4 necrotic damage to the total. You take 1d4 necrotic damage. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher,  the damage dealt by the attack increases by (4d4) for each slot, and you take (1d4) points of extra damage for each slot.