okay here's another silly little AU idea for y'all
YQY brings a strange woman into the sect one day, cheerfully proclaiming that the two of them are getting married. everyone is cautiously happy for him (they've never heard about this woman before? but zhangmeng-shixiong looks really happy, so... yay?) until they notice that he's lost all interest in his most beloved shidi for some reason.
like someone approaches him with news of SQQ dropping by to visit the sect and he'll be like "cool :) anyway, my future wife here...". and it's not like. totally inexplicable. after all, isn't it natural for a man to want to spend more time with the woman he loves than with a random shidi? except it's not some random shidi, it's shen freaking qingqiu!! the man YQY unsheathed his giant cursed sword for on several occasions!! how could he have done such a 180 on him in such a short amount of time?
so YQY's shidi and shimei get worried that this strange woman is some sort of demon or evil spirit that bewitched their sect leader, and they call on SQQ to get out of his marital retreat at the demon realm and come assist them with exposing the villain ASAP. except it only takes SQQ spending half an hour in the company of YQY's fiancée (glaring daggers at him from across the room and making acerbic remarks to his every word) to come to the realisation...
OMFG the sect leader is marrying the reincarnated scum villain