Demon Vault:
0 - Least Daemon
1 - Lesser Daemon
2 - Water Demon
3 - Air Demon
4 - Fire Demon
5, A - Greater Daemon
6 - Greater Moloch
Vault layout:
Code:
######################################
#####..333...111111111111...221100####
!!#....333..11222222222211..221100.###
!!#33.!!!!!.12233333333221.!!!!!#...##
!!333#!A55!!!!3344444433!!!!55A!##.00#
!!44##!655444!!!!5555!!!!444556!###00#
!!333#!!!!!!S!!!!!##!!!!!S!!!!!!!!!00#
!!!33.#!33.44.44.5665.44.44.33S..!!00#
X.!!...S33.44.4455AA5544.44.33S...!!.X
#00!!..S33.44.4455665544.44.33!#.33!!!
#00!!!!!33.44.44.5555.44.44.33!##333!!
#00!!!!!!!!!S!!!!!##!!!!!S!!!!!!##44!!
#00.##!555444!!!!5555!!!!444556!##33!!
##...#!A55!!!!3344444433!!!!55A!#333!!
###...!!!!!.12233333333221.!!!!!...#!!
####.001122.11222222222211.333....##!!
#####001122..111111111111..333...#####
######################################
Suggested danger level: 40+
Notes: disable teleportation for greater daemons
Demons are quite common Chaos servants, and there is lesser vault dedicated to them. I think this greater vault could be quite fitting and different enough from giants/dragons/undead vaults.
Difficulty - Above average (slightly easier then dreaded "big room" vault with 10 emperor liches), 6 artifact locations, almost maximum amount of 5 and 6 monsters, but half of them are in isolated room, and you need to fight only 4 most dangerous monsters at a time. Quite a lot of (5) monsters in central room too. Monsters are progressing nicely - DL 5, 10, 20, 28, 40, 20(very nasty stat drainer), 40(greater moloch).
There are also several ways to shortcut your path to some artifacts.