Complex sentence: Molly foils her plans, convincing Barbatos' master to relinquish the mystical gemstone Twilight that has transformed him from a common frog-leaving Barbatos powerless and returned to his imprisonment in the Dreaming, and the faeries freed.
Split into simpler sentences: Molly foils her plans by convincing Barbatos' master to relinquish Twilight, which has transformed him from a common frog, leaving the demon powerless. He is returned to his imprisonment in the Dreaming, and the faeries freed.