Astor's Fall

You cause a flying creature within range to believe its method of flight has been removed, causing it to plummet to the ground. The target must make an Intelligence saving throw. On a failed save, the creature loses its flying speed and begins to fall. The target may repeat the saving throw at the end of each of its turns, ending the effect on a success. (note: A creature falls up to 500ft at the beginning of its turn if it doesn't have a flying speed).