C219 Sanguinol
It turned out that Mengyue had heard a story before, which meant that before everyone died, they would see this thing you said they saw before. For example, Sister Liu's father, when he died, he would always say that there were two children on the ground waving at him, telling him to leave. Of course, for Mengyue, this was something she didn't believe, but for Mengyue, it was true. For Mengyue