Dungeon Life

In the first book of this thrilling isekai adventure series, a human becomes a dungeon?and soon that dungeon becomes something much, much more . . .
The usual result of a human taking a runaway semitruck head-on is a very sudden, very fast track to the pearly gates. But for one newly noncorporeal man, there's another option: become a dungeon. Feeling sorry for the desperate angel assigned to him, the man relents. Heck, if it doesn't work out, he can always chat with Saint Peter about it later.
Next thing you know, he's a dungeon. Admittedly, a small, run-down, somewhat unimpressive dungeon (more of a house, actually), but you gotta start somewhere, right? Slowly but surely, the new dungeon learns the ropes, building himself up with scions of every creepy-crawly sort he can find; gathering mana; dealing with invaders, delvers, noobs, and annoying guild reps; and gradually becoming a local legend known as Thedeim (get it?).
The more Thedeim's power and reputation grows, the more he becomes a part of his new world?and the more its various denizens become a part of his. But how is a proper dungeon supposed to instill spine-shattering, mind-melting terror in a pack of questing adventurers when it's so much more fun to play along with them?