Vampiric Smite

Cast as a bonus action when making a melee or ranged attack. On a hit, deal an extra 1d8 necrotic damage to target.  If your target is a living creature with at least 1 HP you heal for half, rounded down, of the damage from Vamperic Smite.  Objects hit with this attack can not be mended via the mend spell in the area affected.  In addition, creatures hit with this spell have a festering wound left behind even if healed. Only a Cleric, Priest, or Priestess casting a healing spell can heal the festering wound, but it still leaves a scar behind.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 1