Xie Qi was a manufactured soul, no matter how hard he tried to act human. The people in the underworld argued about him amongst themselves; did he deserve to reincarnate? Could he even reincarnate in the first place? Was his soul made durable enough by the blasphemous humans that created him?

Even so, he is still sent to his next life since his merits were too much not to. From there, he decides his goal; he will not simply be a 'human.' He will become a sage, so he can truly understand why he was brought to existence.

....

Xifeng suffered injustice after injustice at the hands of the cultivators and the immortals. In the burning ruins of what was once her home, what was once her village, she decided that she would become something that could kill them all. That could slaughter them all and restore peace to the mortal world, make it into what it was supposed to always be.

For this, the sages especially chose her to be a sage, one of the last. To end this incessant battle which has gone on and on until the beginning of time and lead humanity into further progression beyond using the world as a crutch.