Lucia, Su Wan's safer was heading towards the gate of exchange to meet Crescence, the warder to start the transmigration. She had been the one who advised and convinced her to transfer Su Wan's soul to the Parallel of the human world. There, lived a girl with the same energy and basics as Su Wan who died less than 1 hour ago. She had a character similar to that of Su Wan so much such that her family won't see the difference.
Also in that world there was the possibility for her to regain what was lost.
Crescence as a warder even though evil, she knew the ins and out of this world and it's parallel. All worlds had parallels be it the human or guardian or even ghilins. She explained to Lucia that a being in each world had
an equivalent in the parllel. A being and it's equivalent could swap places or one could replace the other in the case of his death. For the later to happen however, the must be of the same age when the other dies and the exchange be done less than 2 hours after his death. Ghilins can easily do that as the can travel between worlds at will and change ones time of death. Guardians can only travel between the human worlds and their world of origin making it impossible to transmigrate by themselves. It is simply impossible for humans to travel between realms. But a human can swap and transmigrate with the help of his guardian. Swapping is quite inconsequential as one just has to lose 2 years of his life per swap knowing that guardians can leave up to 5000years. However, transmigration involves erasing the safer's memory and the human's loved ones concerning them. This will greatly weaken a safer as his purpose to protect his human cannot more be fulfill making it uneccesart for him to have powers.
Lucia felt so bad for the life she inflicted to her human that she was ready to loose her powers if it meant she could be happy. It is true Su Wan had a loving brother in her old life but there she couldn't be happy. In this world, she would be respected, loved by many more and have the chance even if slight to regain her lost emotions.
That is what Lucia was taught and what she believes so much reason why she didn't save her when Su Wan fell in the hole.
Crescence as an evil warder gained more powers when a safer died near her so she incited Lucia to do this. She knew many stories about human transmigration and swapping and used that to her advantage. She approached Lucia and gave her some advice together with some informations which she could verify. After some research Lucia realised all she said was true and came to trust her. When she asked her what she gained she said" We warder gain more power when safers get weak due to us. It doesn't mean I have to fight you. If you lose your power after following my advice I will be stronger." Lucia believed and here they are ready to transmigrate Su Wan and kill Lucia for without the need to protect a human a safer doesn't need to exist.
After some incantations, Su Wan's body appeared and all her belongings disappeared from the human world. When Su Wan started disappearing, her memories and Lucia did too.
" Finally, I would be full for 2000 more years" said Crescence while laughing.
Exactly 15 hours after her death, Su Wan Lee was send to the human parallel realm.