Sector Scylla
From Sonic Retro
Sector Scylla is one of two (named) regions in the Twilight Cage, visited by Sonic and friends during Chapter 8 of Sonic Chronicles: The Dark Brotherhood. The sector is presumably named after, or lends its name to, Prefect Scylla, an advanced Gizoid who serves as the co-commander of the Nocturnus Clan army.
Voxai territory dominates Sector Scylla, with their twin colony planetoids Voxai Alpha and Voxai Beta being the two areas which the Cyclone can fly to in-game.