Book type Battle Spirits tend to be trash. Very few are able to be cultivated.
The Treasured Book is a Spirit that allows the user to absorb the spirit ring of any Spirit Beast he killed and turn it into his own abilities. The most unique point was that it doesn't have any attribute limitations. Any Spirit Beast’s ability can be absorbed. After it was absorbed, it can also be used. That means, it is likely that the user has just used an ice spirit ability, followed by a fire spirit ability. This is a very special and limitless Tool Spirit.