Dr. Eggman has unleash a giant dark creature of darkness called Dark Gaia and destroy the world! Dark Gaia rises from the planet's core and plunges the world into neverending darkness. Meanwhile Sonic gains a new form and transforms into an giant muscular monster-like werewolf called the Werehog! He meets up with his new fun, yet mysterious friend, an small unsuspecting creature named Chip who lost his memory. With the help of Sonic’s friends along the way, the two set out to every country to put the world back together by using the Chaos Emeralds, while battling monsters spawned from the Dark Gaia.
