Make a melee attack against a creature within 5 feet of you with the weapon used in the spell's casting. If the attack hits, the target takes normal weapon damage, and then becomes sheathed in necrotic energy until your next turn begins. If the target chooses to move 5 feet or more before then, the target will take 1d8 necrotic damage, and the spell's effects will end. The damage caused by this spell increases at certain character levels.

At level 5, the melee attack will deal an additional 1d8 necrotic damage on a hit, and the damage the target suffers for movement increases by 1d8. These damage rolls increase by 1d8 again at level 11 (2d8 and 3d8) and level 17 (3d8 and 4d8).