Di Jiu is the main protagonist of the webnovel "Ninth In The World"
He was at first a wastrel who couldn't cultivate nor pratice martial art as he was unable to Activate his Martial Spirit Root.
His family was exterminated by Wu Bahu under the pretext that he needed Di Di's Eyes
Having his whole clan murdered leaded to him being forced to leave his homeland.
Di Jiu found a small stone on a mountain and used a void rift opened by the Golden Law to go back to Earth where his precedent incarnation died.
He was able to do that as the small stone was actually a fragment of the Universe Membrane and the Golden Law, The 9th Primordial Law.
We later learn that all of this was instigated by a sect called Abstruse Fire Sect more precisely by GeYi, a doctor, Liang Lu and an Elder from their sect (Liang Lu's relative).
Di Jiu killed them, rescued his sister and destroyed the sect the same way he exterminate the Wu father, son and whole clan.
This Novel is closely related to Strongest Abandonned Son, The Gate Of Good Fortune as we even hear about Ye Mo, Ning Cheng and even see them re-forging their Daos.
In this novel we also learn about Ye Mo's other descendant called "Ye Nianxing", he became good friends with Di Jiu's son Di Wangchuan.He was named after Ye Xing, Ye mo's cousin who disappeared. He was actually at the City Of Good Fortune with Di Jiu and Qin Mutian's orginal body.
As for Qin Mutian (Ning Cheng's enemy) was actually his evil side that he cut who after trapped him and destroyed his world (a universe prototype) he met Di Jiu in the chaos world where Di Jiu ascended to 3rd Step.Di Jiu promised to help him after he got out.
Di Jiu came back after some time because of some situation to the chaos world where Qin Mutian was cuting all the Laws, supernatural power,every technique he practiced to reach the 3rd step as Di Jiu told him to do. Di Jiu's world is still in the Chaos world (the mist where Ye Mo was afraid of) he used his Heavenly Aqua Saber to slash his way out at the same time breaking his Treasured Saber. The Heavenly Aqua Saber then started to evolve the first time Di jiu took it back when he came the 2nd time to help Qin Mutian to ascend to 3 Step.Even After Di Jiu got it back it was still evolving.