"The Greatest Magic" was famously Larry DiTillio's last ever script for He-Man and She-Ra, and even more notably, his last ever script for Filmation! In the episode She-Ra journeys to Orko's home world of Trolla, and from that point on, She-Ra pretty much becomes a guest star in her own series, as the influence and presence of Trolla is so strong! Here is the front cover of the model pack for the episode. Even here you can see that the Trollan's have taken over the cover!
(click on the image to see it at full-size)