Never read a dungeon core story before. I honestly don't see how it can be done and it not run into an awful amount of repetition. I mean the dungeon is trapped in one location right? So it doesn't have much leeway as far as world mapping and showing off new sights and places. And of course you could also have chapters from the monster point of view that leave the dungeon but then....you have to keep doing that to keep showing off more of the world in which case I would rather read from the monster POV then the dungeon.
Either that or I'm just ignorant of dungeon POV stories. Dunno.
That's the main problem all dungeon stories run into. at some point the author just runs out of ideas for the location and then they just change it into not a dungeon story anymore.
Other fixes include giving the dungeon a body so they can leave and go adventuring. giving the dungeon some form of wheels so they can run around the world with the grace of a 500 ton mountain.
The only ones who pull it off off the top of my head have all been short. Don't need a full built world if your only 1-3 books long after all.
girl dies and reincarnates as a dungeon
Your gonna want to add a twist cause as said above that has been done before, alot.