Dia

Light energy converges on a creature you can see within range. The creature makes a dexterity saving throw. This energy erupts with great force, searing the target creature with 3d8 radiant damage. The next attack roll made by the creature until the end of it's next turn has disadvantage.  On a successful save, the target only takes half damage and does not suffer disadvantage on its next attack

At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.