Arcane Break

You shatter the innate magic around your target  - the severance of magic crushes an opponent and leaves them disconnected from their own spells. The target must make a Dexterity saving throw. On a failed save, the creature takes 10d4 force damage and must then make an Intelligence saving throw. On a successful initial save, the creature takes half damage and does not make the Intelligence saving throw. Creatures who fail the secondary Intelligence saving throw are cut off from their own source of magic. When the target attempts to cast any spell, it must make an Intelligence saving throw against your Spell Save DC. Should the target fail this saving throw, the spell is lost and the action spent. On a success, the target is able to cast as normal.