Chengxian AU where there's no war BUT WWX gets de-aged Detective Conan style and while the two of them are freaking out over it and have to present a cover up for why JC's roaming around the jianghu with a child that suspiciously resembles WWX. So on one hand you have the de-aging villain conspiracy, on the other hand you have Madam Yu getting closer to a heart attack from a wholly different set of rumors.
Time travel/reincarnation fics centering around shen jiu should always be like: I am back and I am now obsessed with protecting Qi-ge. Literally, NOTHING ELSE MATTERS INCLUDING ME.