User blog comment:Yuu Chikuwawa/About 9 Sacred Treasures/@comment-24570336-20151104110421/@comment-27148187-20151104175620

http://bravefrontierglobal.wikia.com/wiki/Sacred_Gem

and look to the reward at rank 67 skywalker

http://bravefrontierglobal.wikia.com/wiki/Arena_Rewards