i know you want a dungeon vibe so i only suggest for mechanica to sit and play with or ways to prepare encounters and stuff :)

i'd give FIST a look for some inspiration! its whole deal is easy to sit, create characters, and run a mission, and its Mandelbrot set is straight up a roguelike with tables for interesting encounters and stuff + great tactical extraction vibes

Courier and Snacks for @/Stalhound on artfight