Responses
Basically, the watch to rewind time was only to be used ONCE but timeline 2 sayoung used it again, straining the watch's power, so the 2nd and 3rd world are merging together. Timeline 2 sayoung is using his body to prevent the two worlds from combining so that's why he's roaming around. The watch didn't fully rewind time, it did half of that. (hope that makes sense its been a while since i read the novel ;-;) Yes, timeline 2 CEJ is gone.
So Saeyoung(idk how to spell) from the 2nd world was in the rift that current Euijae had to clear?? And they never met??
If "turning" back time actually undid all that happened, then there wouldnt be rifts that lead to those universes. So 2nd world Sayoung is currently STILL missing 2nd world Euijae. Thats so sadddd wtf