He-Man and the Masters of the Universe - Season 1 Episode 21 The Taking of Grayskull
Overview: Orko thinks that everyone has forgotten his birthday, when Man-At-Arms reports word of strange destruction the town of Becilia. He-Man, Teela and Ram Man go to investigate, and find themselves in the middle of a tornado some very curious effects – one of which is He-Man's sword disappearing, as a result of some strange influence somewhere. Meanwhile, Orko, upset at his birthday seemingly being forgotten, heads off to see The Sorceress, only to find that Castle Grayskull is gone! Skeletor has managed to harness a White Hole, with which he has sucked the castle, with The Sorceress inside it, into a strange reverse dimension, where he is trying to use the backwards laws of the dimension to harness it's powers. He-Man, Battle Cat and (unintentionally) Teela head into the White Hole to try and stop this latest evil attempt...