Book of Earth

The Book of Earth contains part of the ancient wisdom of Shinsei. It is an ancient book bound in dark vellum and steel with the symbol of earth stamped upon it.

Enlightenment Challenge
The challenge to win this book was

"The smith who can craft a helmet strong enough to shatter one thousand blades shall keep the Book of Earth."

This challenge was completed by Kaiu Sugimoto when he persauded the Badger Clan to focus on a potential Oni attack instead of launching a needless war against the Yobanjin who were also aligned against the Oni.