After gaining some of her past memories, Bing Shi was able to keep her current self, refusing to show any adverse after-effects.
Ru Quan, on the other hand, had a tough time keeping his "current" self when his "past" lives kept fighting for dominance. Two distinct personalities from different timelines remained stubborn, switching constantly depending on the situation.
To make matters worse, he felt as if he was being eaten up by a black hole, slowly disappearing into nothingness. He was going through the same identity crisis that Ziek did, which was all due to the immeasurable jealousy not only towards Xuan Mu but also Ziek.
(Mr. Jelly): If you remembered the past, and there's a man you loved more than me. Who would you choose?
And let me know in the comments what arcs you want to see. :)