Beshadowing Strike

You brandish the weapon used in the spell’s casting and make a melee attack with it against one creature within range of the melee weapon. On a hit, the target suffers the weapon attack’s normal effects, and then becomes sheathed in swirling dark shadows and has disadvantage on the next attack roll it makes before the end of its next turn.

This spell’s damage increases when you reach certain levels. At 5th level, the melee attack deals an extra 1d8 necrotic damage to the target on a hit. The damage roll increases by 1d8 at 11th level (2d8) and again at 17th level (3d8).