canons for su she standalone? or if those overlap with your previous post too much, either xisang or SS&-or-/-NHS?
Headcanon: He comes from a merchant family. That'd account for the feeling of being look down upon by all those damn nobs who wouldn't know hard work if it hit them in the face, yet dare to judge him for coming from a background that provides a service that's useful to them
Heartcanon: He truly meant well in creating his own sect. Yeah, it was due to a fallout with the Lan sect also, but I think he really wanted to create a sect that would be less dependant on blood ties, and gave a truer chance to people of lesser backgrounds sadly that ideal came second to his devotion to jgy ahaha rip su she's disciples
Gutcanon: He helped jgy come up with the song that killed nmj. I think the text of the novel implies it was all jgy's work, and that he's the one who taught su she how to twist music that way? But since ultimately sms is the one who did have a formal background in musical cultivation, I just think it makes sense for him to have been an active participant in the remix
Junkcanon: tbh, nothing in particular. He's handsome in the Lan style, so probably kinda popular and wouldn't have had any problem finding partner if not for... a certain problem. Which I think is also why he doesn't appear to be married ahah :D
Spleencanon: not a specific thing as such, but I feel that in cql particularly, su she is 100% right in his dislike of Gusu Lan. They did treat him and other outer disciples like shit. And he's right in his dislike of lwj too, because it's damn right that lwj's family connection have protected him from consequences of his actions. Hey, Wangji, remember when you looked down on Su She trying not to die in the middle of a slaughter, and then you played high and mighty after defending a known murderer? (I mean, yeah, in cql sms was partly responsible for the slaughter in nightless city but... some of it was ALSO just wwx so???)
anyway, Su She was right, fuck the Lan