"Now that I have broken through to the Ninth Level of the Void Peeping Stage, the Entering Void Realm is only a step away... It is time to contact the owners of the other eight Jade Swords."
At some point, Duan Lingtian had retrieved a crystal-clear Jade Sword from his Spatial Ring.
This Jade Sword was precisely the key left behind by the Young Master of the Wuya Sect to open the Sword Emperor's Treasury.
Chapter 591