"Hmm?"
Xiao Yi's pupils slightly contracted.
To imprison the Thunder Mad Dragon, condensed under his Six Dragons Sky Covering Formation, at least forty thousand dao strength, nearing fifty thousand, is needed.
Of course, the Six Dragons Sky Covering Formation, as the Heavenly Mechanism Palace Master's esteemed formation, has power far beyond this.
It's just that Xiao Yi's current level is still too low.
Adding to this, the power of the formation itself is inherently related to the strength that supports it.
Presently, the Spirit Stones he used to set the formation are not that numerous.
Thousands of Spirit Stones amount to about one Spirit Vein.
Xiao Yi still remembers when he fought Tu Qianqiu, he used merely half a Spirit Vein's worth of Spirit Stones to defeat Tu Qianqiu.
Yet, Tu Qianqiu was only a forty thousand dao powerhouse.
