Vampiric Smite

The next time you hit a creature with a weapon attack before this spell ends, the weapon glows with red lightning as you strike. The attack deals an extra 1d8 necrotic damage to the target. On a hit, you gain half of the damage dealt as hitpoints. At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the extra damage increases by 1d8 for each slot level above 1st.