To those who didn't understand i'll repost the explanation i wrote in the comments to be on top.
"
What happened is as follows ("Yi Kui" is the original name of "I Que"):
Yi Kui and Lin You have met in the past and fell in love, but Lin You kept dying over and over because he met Yi Kui in every reincarnation, most likely because they were entagled by fate. [Note that Yi Kui didn't die a single time in the past due to his long lifespan]
To stop this acursed fate of Lin You, Yi Kui met the Witch of the East and asked to relieve Lin You of his fate, to which she did but the price to pay was a life in return and a promise to be kept.
Lin You was saved and forgot of the past he shared with Yi Kui which disappeared from the world.
After that, in the modern world the 2 souls still entagled by fate meet again in a new life to which represents the main story you've seen.
P.S.: The promise made to the Witch was that they may come visit her in the future and play with her.
"
"
What happened is as follows ("Yi Kui" is the original name of "I Que"):
Yi Kui and Lin You have met in the past and fell in love, but Lin You kept dying over and over because he met Yi Kui in every reincarnation, most likely because they were entagled by fate. [Note that Yi Kui didn't die a single time in the past due to his long lifespan]
To stop this acursed fate of Lin You, Yi Kui met the Witch of the East and asked to relieve Lin You of his fate, to which she did but the price to pay was a life in return and a promise to be kept.
Lin You was saved and forgot of the past he shared with Yi Kui which disappeared from the world.
After that, in the modern world the 2 souls still entagled by fate meet again in a new life to which represents the main story you've seen.
P.S.: The promise made to the Witch was that they may come visit her in the future and play with her.
"
i'm thinking...