Mana Break

The next time you hit a creature with a weapon attack before the spell ends, your weapon crackles with hungering arcane energy that burns a spellcaster that has already tapped into their natural energies. The target must make a Wisdom saving throw or take an amount of extra arcane damage equal to the mana they have spent (or the mana cost of the spells it has used with Innate Spellcasting), or half as much damage on a successful saving throw.

This spell ends early if you cast it again or cast another smite spell, such as shackling smite or lightning arrow.