Darkling Blade

Shimmering, opalescent energy congeals around the weapon used in the casting of this spell, creating an oily trail where it passes. When you cast this spell, make an attack with the weapon used in its casting; on a hit the target's next weapon attack deals half of its normal damage. Regardless of if the creature makes a weapon attack, this effect ends at the start of your next turn.

This spell gains damage as you grow stronger. At 5th level, the attack deals an additional 1d8 necrotic damage. At 11th and 17th level, this damage increases to 2d8 and 3d8 respectively.