Su Mo's Bai Yan clone cultivated the two soul arts, Heavenly Thunder Fiery Flame and Thousand Souls Ten Thousand Soldiers, in peace within the secret chamber.
The difficulty of these two soul arts was indeed considerable, but to Su Mo, they were nothing out of the ordinary.
He needed only half a month to cultivate both soul arts to a respectable level.
Take Thousand Souls Ten Thousand Soldiers, for instance. Though he could not yet be said to wield it with consummate mastery, he had essentially brought it to great accomplishment.
This soul art was extremely miraculous. It could use the soul power within his body to conjure Thousand Souls Ten Thousand Soldiers with a wave of his hand. Most importantly, it did not consume an excessive amount of soul power.
Of course, since he had not cultivated it to perfection, Su Mo could not truly conjure Thousand Souls Ten Thousand Soldiers at present. However, conjuring several hundred troops posed no problem.
As for Heavenly Thunder Fiery Flame, it was the primary cultivation technique. It greatly enhanced the strength of Su Mo's Bai Yan clone, an improvement at its very foundation.
However, Heavenly Thunder Fiery Flame was still quite far from great accomplishment, because this technique required the power of lightning and blazing fire to temper one's soul power.
Although Su Mo could condense lightning and flame power with Law power before using them to temper his soul power, his Law power could not currently display much might. Thus, his attainment in the Heavenly Thunder Fiery Flame soul art remained some distance from great accomplishment.
At this point, Su Mo temporarily stopped cultivating the two soul arts and prepared to raise his cultivation by another level, reaching great accomplishment of Fortune Realm.
Although advancing now still seemed too fast, some