You brandish the weapon used in the spell’s casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack’s normal effects, and becomes suffused with draining, necromantic energy until the start of your next turn. If the target makes an attack before then, the target takes 1d8 necrotic damage, and the spell ends.

At Higher Levels. At 5th level, the initial melee attack deals an extra 1d8 necrotic damage to the target on a hit, and the damage the target takes for making an attack increases to 2d8. These increase again at level 11 (2d8 and 3d8) and at level 17 (3d8 and 4d8).