From the Publisher's website Spirit Warrior Empire is the first expansion for Mecha! The focus of this supplement are the Azteca, a space faring race whose holdings comprise what is now known as the Spirit Warrior Empire (hence the name of the book - clever, huh?). Included in this book are more missions, new mecha designs, and the complete history of the Azteca and their portion of known space. If you enjoy the anime-style wargaming, then Spirit Warrior will give you whole new realms to discover in the Mecha! universe.