SD Gundam Side Story: Sieg Zeon Chronicle

In an era removed from our own, there is a place known as the Saddrac World. In this world, humans and mobile suits live in peace... One day, however, accompanied by a flash of lightning, a gigantic shadow looms suddenly over the land. This shadow belongs to the Satan Gundam, the Demon King of Zeon. The Demon King declares his intentions to rid the world of humans and create a place for mobile suits alone to live. His evil influence extends as far the remote Lacroa Kingdom, wherein Revil, King of Lacroa, chooses a single hero and orders him to save the very world. The name of this hero is Knight Gundam, and his adventure starts here...