This wiki has backgrounds, header, aura colour, and the like that change depending in page, https://hollowknight.fandom.com/wiki/Knight
Like, here is an example:
https://hollowknight.fandom.com/wiki/Grimm
https://hollowknight.fandom.com/wiki/Pure_Vessel
How do you think this can be replicated, I only know how to change these across all pages, dont know how one could change them in a page itself.