In “Unicorn: Warriors Eternal,” an evil force is looming across the dark, thick-aired streets of industrial revolution London when a group of heroes dubbed Unicorn are accidentally reawakened in the bodies of teenagers instead of adult hosts they’ve embodied in the past. Melinda, a powerful sorceress, Seng, a cosmic monk, and Edred, a warrior elf. With distorted memories and their magical abilities weakened and fragmented, the trio must work together with help from their steam-powered robot, Copernicus, to unravel the mysteries of their pasts and present that will reveal their path to defeating a timeless threat.