This was because one of the conditions for contracting the Beast Spirit's Soul involved the purity of soul power.
Lin Yuan had consumed the Suzerain Silver Stamen Gold Luster Cassia nectar and cleansed his soul of all impurities. He was fully capable of contracting the Beast Spirit's Soul.
The second condition involved Willpower Runes.
The Beast Spirit's Soul and Source Sand had a similar contraction method. Both required the use of Willpower Runes.
The difference was that the Source Sand needed two Willpower Runes while the Beast Spirit's Soul only needed one.
However, the Source Sand had not been picky when it came to Willpower Runes, but the Beast Spirit's Soul needed a soul-related Willpower Rune.
If this was happening yesterday, Lin Yuan might have been troubled over the requirement for a soul-related Willpower Rune. But now, he did not have any cause for worry.