You fling a thin needle of darkness at a creature you can see within range, injecting them with corruptive magic that taints their mind and fills them with doubt. Whenever the target attempts to cast a spell that targets a creature friendly to them, they must make an Intelligence saving throw. If they fail, they take 3d8 psychic damage, their spellcasting fails and the spell is lost. If they succeed, the corruptive magic is broken and the target is freed from the effects of this spell.