Sonic Adventure 2

Story

When Eggman learns of a secret weapon from the diary of his late grandfather, Professor Gerald Robotnik, he infiltrates a high-security G.U.N. facility and brings it to life with a Chaos Emerald. The weapon - a black hedgehog and self-proclaimed "ultimate life form" named Shadow - offers to help Eggman conquer the world and tells him to meet up with more Chaos Emeralds at the abandoned space colony ARK. Shadow goes to Central City and meets G.U.N. troops there after stealing an emerald. Shadow has sworn to fulfill a promise to a girl, Maria, which he interprets as revenge. Shadow blasts his way through the forces and encounters Sonic. After a brief confrontation, Shadow escapes and G.U.N. captures Sonic, whom they mistake for Shadow. Meanwhile, Knuckles encounters Rouge and Eggman, who are trying to steal the Master Emerald. He stops them by smashing the emerald and searching for the scattered shards. Rouge, spying for the government, makes her way to Eggman's base and the ARK. There, Shadow shows Eggman the Eclipse Cannon, another superweapon created by Gerald, and reveals his plan: to charge the cannon with Chaos Emeralds and use it to conquer the world. Rouge appears and offers them a Chaos Emerald to gain their trust.