Among beasts of the same tier, those of the spirit series naturally possess stronger spiritual power.
Even the most common spirit-series Guardian Beasts, with means to amplify their spiritual power, would find it hard to double their own strength.
What Fang Mu lacked most in combat were control-type skills, and "Spirit Extraction" could be considered an extremely powerful control-type skill in his arsenal.
The Spirit Mayfly applies control-type skills to its target, and because its body is extremely small, it's hard to detect.
Thus, this form of control is not only difficult to prevent in advance but also hard to counter.
The Spirit Mayfly: Extreme Accumulation has three evolutionary paths, which are Spirit Mayfly: Spirit Jump, Spirit Mayfly: Soul Slash, and Spirit Mayfly: Soul Annihilation.
Among these three evolutionary paths, only the Spirit Mayfly: Spirit Jump is related to spiritual power.