i know nothing about Les mis, how is it canon to the shaperaverse?
I saw this in the evening and was like "no im too tired to answer this" so now that it is a normal hour for using my brain (3 in the morning) I shall try to provide an explenation!
Basically. The way themes and characters work in les mis is EXACTLY how they work in the Shaperaverse minus the meta worldbuilding.
The narration of the book itself feels like its own character (it isnt said explicitly but that character is probably the author- victor hugo, much like how paul shapera himself also cannonically exists within the shaperaverse) and said narrator has a personality and famously goes on tangents.
There are also characters that seem to be aware of the existance of a narrative and CONTROL IT within the book. It is something the fandom talks about a lot and its never explained in les mis with worldbuilding, its just there, but it functions the same way posthumams in the shaperaverse do.
This goes for themes that connect characterd - the character of fantine and the characters of enjolras famously share perallels and their arcs complete eachother! Several people in the fandom have said that they would like to see versions of the musical where both are played by the same actor, and my friend chana @ofpd literally made a post that goes "enjolrad appeared as a 17 year old revolutionary the day fantine died". There is an understanding in the fandom that those characters are connected to eachother in the same way reincarnations in the shaperaverse are conmected to eachother, but there isn't the worldbuilding of the shaperaverse to make it "canon".
(I actually wrote a fic about enjolras being a reincarnation of fantine with the help of @underwhelming-universe . And we basically had to just write in the worldbuilding parts, because the characters were already perfectly set up by victor hugo to have the reveal! It fits so neatly its actually insane. )
There is even a character who gets their worldview shattered, and jumps off into the siene, which is very rmeinicent of flowering of posthumans like david adams.
The themes work exactly the same, minus the in-work worldbuilding, and fans keep talking about how characters work in a way that is literally JUST the shaperaverse without the worldbuilding.
And if you take the worldbuilding of the shaperaverse and apply it to les mis, it fits perfectly.