After Traveling Through Demon Slayer, I Am the Third Creature

System + pseudo-infinite streaming + CP purgatory + plot + HE Su Mianxue, an international student at the University of Tokyo, accidentally activated a certain quest line system of Demon Slayer: Kimetsu no Yaiba, but when she came to the world of Demon Slayer: Kimetsu no Yaiba, the system told her that it was the dispatch system of Gintama next door. In order to compensate her, it gave her the attribute of "Yato Usagi". In order to change back to the original system, Su Mianxue worked hard to find the special NPC for her quest line. With the help of the system, a large number of Demon Slayer members who rescued Spider Mountain and helped Yoya to alleviate the curse gained trust. And found the special NPC Purgatory Xingjulang and worshiped him as his teacher. After understanding the difference in strength between humans and ghosts, Su Mianxue knew that someone would be sacrificed if she followed the plot, causing the progress of her mission to be slow. So she decided to use her clone to go to Wuhan to weaken Shangxian's combat power. In order to prevent Wuhan from reading her thoughts, she sealed herself. But the other person she grew up with happened to be the one who inherited the darkest memories. A swordsman who raises ghosts should commit hara-kiri...