ignoring the fact i havent posted in ages but am currently bit by the p5 bug, consider:
a mishima palace au, but its similar to futabas palace, born (originally) by his guilt from being forced to help kamoshida, the years of bullying and physical abuse, even his own longing to kill himself to escape it all
also consider: his shadow living up to its name, and although stable, its a barely tangible being, dissolving and breaking away at the edges, invisible, unless specifically looked for in the real world (which even then isnt permanent - he doesnt think hes interesting enough to be cared about for long)
of course, his palace shifts after he becomes the phansite admin, but it also feeds into his guilt because he knows hes doing something wrong but for once in his existence he has meaning, even if he truly is still just barely not invisible
im not sure quite yet what form his palace takes, but im leaning towards a multi floored labyrinth
