What happens when you give an unhinged fangirl the nearly limitless creative power of a dungeon?

Cyd died a fairly average under-achieving human on Earth only to find herself reborn inside a Fantasy world as a dungeon core. It's nothing like the books she's read; She doesn't have to worry about her core being destroyed by rabid adventurers, fighting with other dungeons for territory, or stopping some great undead scourge from taking over the realm. Her job is to act as a prison for powerful Boss Monsters and to grow as much as she can to unlock more Boss Monsters to guard.

The entire process sounds boring and uninspired, so Cyd is determined to take as many liberties as she possibly can. The parameters are pretty flexible and Dungeon cores were never supposed to house an intact human mind...

Maybe Cyd can utterly break the system?