Chilling blade

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 then becomes enshrouded in necrotic flames. The target cannot regain hit points this turn.

This spell’s damage increases when you reach certain levels. At 5th level, the melee attack deals an extra 1d6 necrotic damage to the target on a hit at 5th level, damage rolls increase by 1d6 at 11th level (2d6) and again at 17th level (3d6).