Distort Verbonics

If you see a spell being cast that requires a verbal component. You quickly react making a small gibbering piece of flesh near their ear to try, and frazzle the caster, making them stutter the verbal component of the spell, Target must make an arcana check against your intimidation check if they succeed there spell is cast normally, on fail if the spell requires an attack roll it's made with disadvantage, and any resulting saves from there spell are made with Advantage. To get advantage on the spell saves they have to be able to see, or hear the caster.