Decaying Impalment

Make a melee spell attack against a creature you can reach. On a hit, the target takes 1d10 necrotic damage. Next 2 turns must roll 1d4 Necrotic damage

Wisdom saving throw to avoid. Holy characters get advantage, Any alignment not good has disatvantage

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d10 for each slot level above 1st. and 1d4 rises to 1d6