Arcane Smite

The target takes an extra 2d8 Force damage from the attack.

Alternatively, you can charge and hold this spell's arcane energy by casting it as a Bonus Action without a trigger. When you do so, the spell's duration becomes Concentration, up to 1 minute, and its damage increases by 1d8. You can then release the spell's charged energy on a later turn before the spell ends as a Bonus Action in response to its normal trigger.

If your Concentration is broken before releasing the charged energy, it becomes unstable and explodes. You and each creature within 5 feet of yourself must make a Constitution saving throw or take 1d8 Force damage.

Using a Higher-Level Spell Slot. The attack's extra damage increases by 1d8 for each spell slot level above 2.