Doubt

You fill a creature you can see within range with immense doubt in themselves and their abilities. The target must make an Intelligence saving throw. (Using the caster's spell save DC) On a failed save, the target deals 2d8 less damage with every attack and rolls with disadvantage. On a successful save, the target only rolls with disadvantage. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage decreases by 1d8 for each level above 3rd.