Residence to King Shadow
After Shadow took over, he moved the world capital to Portal, a merchant city on Angel Island. From there, Shadow and Sally ruled from Castle Mobius. The castle then had a dungeon, which held prisoners, most notably Rotor, Cobar, Sonic, Tails, and Lara-Su. Cobar was presumably killed while in the dungeon, while the other 4 were freed by Knuckles. The castle was also home to Sonic's coup d'etat that same day. (StH: #166, #167; SU: #5)
Takeover by the Dark Presence
Following the Shadow fiasco, the castle was home to Sonic and his royal family. The site was also the scene of a celebration for Sonic's 5-year reign (the Five Years of Peace). The family was nearly killed by Lien-Da and the Dark Presence, but Silver the Hedgehog showed up and blew up the missile. The victory was short-lived as the Dark Presence infiltrated the castle, taking all the inhabitants prisoner except for the royal family, three of whom fled to a safe room with Silver while Sonic escaped and joined forces with Lara-Su, Melody and Skye Prower. (SU: #5, #6)
- Royal Family:
- Catacombs: The catacombs of Castle Mobius are where powerful weapons, creatures and prisoners are held so they may cause no harm to the rest of the planet.
- Living Room: A comfortable room for the royal family to sit and relax in and watch television on the sofa.
- Panic Room: The panic room, otherwise known as the "special hidey-room", is an emergency room where the royal family goes to after heading down a long tunnel in times of emergency.
- Throne Room: The throne room is where the current monarchs reside.
- The Nursery: The bedroom where Sonia and Manik sleep.
- The design of Castle Mobius is similar to Castle Acorn in some ways.