Team Sonic discovers the emergence of The Ultimate Lifeform, Shadow The Hedgehog. Meanwhile, Mecha Sonic, still in Sonic's mind, starts to ramp things up in an overarching attempt to fully control Sonic's body.
Fear of the Master Emerald being taken by Shadow, Knuckles takes a trip to Jungle Ruins to find only Rouge: a petty theft with an eye for anything shiny eyeballing the Master Emerald.
Right after the epic battle between Knuckles and the mysterious Shadow The Hedgehog, Sonic and The Gang are on the hunt for the faker. Meanwhile, The Chaotix have been hired by G.U.N. for a secret mission that will push them to their limit
Possession Arc: Part 1 - Sonic and Gang set their plans into action. Finding Dr. Eggman's backup base, destroying the main base, and finding the Chaos Emeralds. Plans fail after Sonic and Shadow run into each other and have a Rematch.
