You conjure forth a glowing white tendril formed of the sinister, necromantic Dead Mists, which lashes out at a foe you can see within range. When you cast this spell, you can empower it with your own life essence by losing 5, 10, or 15 hit points when you cast it. When you do so, treat the spell slot used to cast the spell as being one level higher for every 5 hit points lost, up to a maximum of 9th level. Make a ranged spell attack roll against a creature within range. On a hit, the target takes 3d8 necrotic damage.