Shadow the Hedgehog

Long story short, Shadow was freed from the Capsule and managed to escape to Tokyo, where Team Sonic, Tails, and Knuckles—or rather, your brothers—met him face to face. And you thought your brothers were just training or fighting Eggman's robots.

Well, in short, Shadow was able to defeat your brothers and all three of them were tired and wounded with bruises, and you, having learned about this, immediately went there.