Heyo. So I finished naming all my fairy nobles for a side project and one of them has the secondary duty of "the Duke of the Mysteries Below". When I wrote that I was thinking something akin to the Underdark from the Forgotten Realms, a massive convoluted labyrinth of tunnels, underground lakes, and portals to the more cosmic realms of darkness. I want it to be gorgeous and terrifying at the same time, but I don't think my writing or world building ability is up to same level as my vision. Can you guys help me out?