Black Exhalation

You exhale a 30-foot cone of deadly spores.

Each creature in the cone must make a Constitution saving throw against poison. If the saving throw fails, the creature takes 6d6 poison damage and loses 1d4 points of Intelligence. With a successful save, the creature takes half damage and loses no Intelligence.

A creature that loses Intelligence because of black exhalation must repeat the saving throw at the end of each of its turns. If the saving throw fails, it loses an additional point of Intelligence to a minimum of 0; if the save succeeds, the spell effect ends.

• If the creatures inteligence drops to 3 or below the creature can't cast spells, activate magic items. 
• If the creatures inteligence drops to 1 the creature also can't understand language, or communicate in any intelligible way. The creature can, however, identify its friends, follow them, and even protect them.
• If the creatures inteligence drops to 0 the creature is stunned until it regains at least one point of Intelligence.

Intelligence loss is permanent until restored by magic such as greater restoration or more powerful magic.