 Because of its technical limitations, Weta subsequently moved to the Syflex system for "The Return of the King".Because they were turned to wraith-like versions of their former terrible selves, tall, slim actors wearing prosthetics and costumes were used to portray the Nazgûl or "Ringwraiths".Filmed on a studio set, the setting and appearances of the Ringwraiths were later edited to look chaotic and terrible.