Drain smite (5e Spell)
From D&D Wiki
|Casting time:||1 bonus action|
|Duration:||Concentration, 1 minute|
You imbue your weapon with your faith so that it leaches life from your target. The next time you hit a creature with a melee weapon attack during the spell's duration, life energy is sapped from the target, dealing an extra 1d6 necrotic damage to the target. Additionally, the target must succeed on a constitution saving throw or take an additional 1d12 necrotic damage, which the caster regains as healing.