So there's one thing that I think they briefly explained but didn't elaborate on. Li Tianxi (the sister)'s ability is to possess a person and experience what they're feeling emotionally and physically. Since the brother is in control when using his power with hers, it would explain the little details about how he wasn't seemingly in pain after being stabbed in his mother's body and why they exit Emma's body before tossing her off the ledge in season 1. They should've done a better job at explaining this though cause I didn't even find out until I read the wiki page of her ability.
What I really wanna know is more about the powers cause after watching this episode I realized that Lu Guang doesn't have the ability to go back in time, he can just see memories of the past much like what Li Tianxi was doing. Going back in time is Cheng Xiaoshi's ability, so it must have gotten transferred over to him like how Qiao Ling maybe might have a power now? Their powers seem more connected than we may realize
Overall your personal rating, even if you have gripes with certain things, is still a good one lol. This is your own experience and entirely based on what you prefer when watching shows. I think I gave it a 9 or a 9.5, one of the two