Eldritch Tendrils

You conjure writhing, spectral tendrils of arcane energy that coil around your arms and strike in tandem with your blows. While this spell is active, when you hit a creature with an unarmed strike, the attack deals an extra 1d4 damage of a type you choose when you cast this spell (necrotic, lightning, cold, or fire). This extra damage increases to 1d6 at 5th level, 1d8 at 11th level, and 1d10 at 17th level.