True Guardian

Episode 3
The True Guardian first appeared in this episode, where he is summoned by Bass and Aeon after Sonic refused to give over the Stone of Chaos. Sonic decided to fight the Guardian himself while X and Zero go find Bass and Aeon and Shadow takes Link to safety. Sonic goes Super to fight him.

Episode 4
Sonic and the Guardian have a small battle with each other in this episode.

Episode 5
Sonic finally destroys the Guardian and reclaims the Stone of Chaos

Trivia

 * The True Guardian's design is basically a supersized version of Slash Beast from Mega Man X4.
 * The True Guardian only has one line of dialogue in this series.