Void (SatAM)

The Void, known to Naugus as Sanctuary, is a location that appears in the Sonic the Hedgehog television series. It is an alternate dimension discovered by the sorceror Naugus, and Dr. Robotnik devised a means to enter it. Robotnik used the Void as a prison for his enemies, including Naugus and the King.

Description
The Void is vast and largely empty. The only land and structure is made entirely of crystal, including Naugus' Sanctuary and a crystalline version of the King's castle, although the King stated that all of these are illusions created by Naugus. Within the Void, Naugus can control and re-shape the crystals as he sees fit and use his magic to do anything except leave the Void.[1]

The Void can be accessed by means of portals. These portals are pinkish-purple vortices, with yellow rings or spirals radiating inward. These portals provide incredible suction into the Void, making the dimension almost impossible to escape. Only someone with Sonic's level of speed is able to break free.[1]

Even after his years of imprisonment, Naugus claimed that there was much about the Void that he did not yet understand. In particular, he was unaware that prolonged exposure to the Void would make him and the King unable to exist outside of it. Attempting to leave the Void would cause the Void to draw their life force, turning them to crystal, and the only way to prevent it was to return to the Void so that Naugus could control it.

History
The Void was discovered by Naugus, and his associate Doctor Robotnik devised a means to enter. Naugus ventured inside to explore, using threats of violence to ensure that Robotnik would bring him back. However, as soon as Naugus was inside, Robotnik sealed the portal and ordered Snively to delete all retrieval programs. From that point onward, the Void served Robotnik as a place to dump his most unwanted enemies.

Shortly afterwards, Robotnik staged his coup of Mobotropolis. After overthrowing the King, Robotnik trapped him in the Void as well.

Many years later, Robotnik attempted to imprison Sonic the Hedgehog in the Void to. Using Ari to lure Sonic to a secret fortress, Robotnik trapped Sonic in a giant game of pinball, with a portal to the Void instead of a pinball drain. Ari had a change of heart and rescued Sonic, who managed to destroy the pinball bumpers and flippers with a Power Ring. Robotnik set the pinball fortress to self-destruct, and it was sucked into the Void, along with Ari, but Sonic was able to escape thanks to his speed.

Eventually, Naugus was able to learn how to open a portal connecting Mobius and the Void, from within the Void. He still was not able to escape, but he was able to send a small artifact back to Mobius, disguised as a ring of the Mandaras. Sonic saw the Void in the Great Unknown, and found the Mandaras ring, which he took back to Princess Sally. When activated, the ring brought Sally and Bunnie Rabbot to the Void, where Naugus used them as bait to draw in Sonic. Disguising himself as the King, Naugus tricked Sonic into freeing him; Sonic also freed the real King and Ari, along with Sally and Bunnie. However, because Naugus and the King had been in the Void for so long, it started drawing their life force back into it, turning them into crystal. They were forced to return to the Void so that Naugus could stabilize their condition.

Trivia

 * Writer Ben Hurst revealed that, if Sonic the Hedgehog had not been cancelled after the end of Season Two, it would have been revealed that following the destruction of the Doomsday Project in the season finale, "The Doomsday Project", Robotnik had been sucked into the Void. The eyes at the end of the episode were Naugus' eyes peering out of the Void as it closed.Snively would attempt to take control of Robotropolis but fail, leading him to open the Void and free Naugus, Robotnik and the King.