Yes, the guy in red, Wei WuXian transmitted his soul into the paper man, but he didn't go to the past. He went to investigate Jin GuanYao (the guy in yellow with a hat), witnessed his quarrel with his wife over a letter stating that Jin GuanYao lied to his wife about the death of their child and many other things. That quarrel lead to the wife being controled and imprisoned in a chamber behind a copper mirror. In that chamber Wei WuXian discovered the missing head of the corpse he and Lan Zhan (the ML in white, WuXian's compnion) were trying to assemble. Then the resentment of the head was soooo strong that Wei WuXian was pulled into empathy with it (the same thing that happened before with the ghost of the little girl). During the empathy he experienced the past with the head's owner, former leader of the Nie Sect, and saw how he was killed by Jin GuanYao. Then the empathy ended but the paper man was discovered by Jin GuanYao and he had to run and return to his body. That is the beginning of this chapter.
I hope this helped, but since this manhua skips a lot of details, please go read the novel, (link is in the comments below) it will explain every confusion you might have, not to mention it's such a good read!
Thank you very much for ur help (⌒▽⌒)
i think im dumb because i dont undersatnd wtf is going on i have been confused from the part where the main dude in red like transmitted his soul into the paper man thingy and went to the past so basically from chapter 134 if anyone is willing to expalin this to me it would be much appreciated ╮(￣▽￣)╭