He investigate jin guang yao and tried to find evidence about his crime. In the process he found hidden room and there is Nie Mingjue's head that sealed. He does emphaty (like ability to swim into memory(?)) to see what happen between Nie Mingjue and Jin Guangyao in the past.
I suggest you to read again if you confused haha. It's normal to get confused 'cause the update is slow
And please read the novel.. There you'll find more detailed explanation about the whole story
I'm sorry if my word is messy, I'm not really good in english โ(โ โยทโฯโยทโ โ)โ
I appreciate it, thankyou.
I can't follow anything anymore after WW turned into a paper