The gap between Foundation Stage and Spirit Stage was like a giant river, and the difference in power and cultivation for those who managed to cross it was vastly different from those who hadn’t. If Fang Xing managed to increase his own battle prowess in such a manner, he’d be able to beat Ye Gu’yin like a wife even if she had the zither in hand. She was a so-called "half-step" away from Foundation Stage, but she still wasn’t actually in Foundation Stage and wasn’t able to bring out the full power of that Ancient weapon.
By Fang Xing’s estimations, that woman had been able to use no more than thirty percent of the Phoenix-Fear Zither’s full power. Of course, this mere thirty percent power was enough to create a wide gap Fang Xing couldn’t cross when the two of them were both in Spirit Stage, but if he was able to break into the Foundation Stage, there would no longer be any need to fear her.