Wilting Smite (Sangromancy)

As part of casting this spell, you must expend two hit dice or the spell automatically fails. If you do, the next time you hit a creature with a melee weapon attack during the duration of the spell, blood flows over your weapon then desiccates into black spores falling onto the target of the attack, and the attack deals extra necrotic damage. Roll the hit dice expended to cast this spell, and the total equals the amount of the extra necrotic damage. Additionally, the creature loses all resistances it has until the start of your next turn.