Tomb Raider: Legend
Sonic isn't the only unexpected video game hero to wield Excalibur. The seventh Tomb Raider sent Lara Croft to locations like Bolivia, Peru, Japan, and Kazakhstan in search of fragments of the sword so that it could be reforged, also picking up Lancelot's shield along the way. Finally she returns to England, where she discovers that the final resting place of King Arthur is a tomb hidden underneath a museum exhibit's recreation of the same tomb (how's that for meta?). There she learns the secret of reforging Excalibur and swaps her twin pistols for it, making her technically another candidate for England's once and future king. The fanfic about her battle for the throne with Sonic surely already exists.