Lan Xichen was confronted by the truth at the end of everything. He has to deal with the pain and guilt of that for forever especially the complicated feelings that would come from his relationship with jgy
Jin Ling’s progression was only normal. He’s now sect leader. Yeah he’s probably a little more traumatized than he was with how whole life being based on a bunch of lies but he still had people there for him. With some therapy (that he won’t get) he’d probably be okay later and be sect leader like he’s supposed to, just younger and more abrupt than he was supposed to.
Nie Huaisang will simply live the life was already living with a bunch habored chunk removed(replaced by a different kind of chunk). He’ll have the satisfaction of saying he did it, he avenged his brother but of course something will always be wrong. He will live the life he’s made for himself, he knew where he would end up let’s be real.
Wen Ning and Jiang Cheng however. That could be another longer post. It’s a toss up between both of them but it’s most likely Wen Ning because he’s literally a corpse.
But it’s definitely not Lan Xichen, I’m sorry