The Mana Temple is found on its own level, MT, the last level of the UL, the unreal cave system. The UL is a side branch off the main CoC at D: 46 or D: 47. The layout, on the right side of the level, is as follows:
#################
#........./.....# ############################
#.........#####.################### #^^^^^^^^^^^^^^^^^^^^^^^^^^#
#.........# #.........../.......# #^########################^#
#.........# #########.###.......# #^#......................#^#
#.........# #...# #.......# #^#......................#^#
########### #####.### #.......# #^#................###...#^#
#.....# #.......# #^#.................#....#^#
###############.##### #.......# #^1................._....#^#
#...............# #.......# #^#.................#....#^#
#.........#.##### ######### #^#................###...#^#
#.........#.# #^#......................#^#
#.........#.##################### #^#......................#^#
#.........#./.....+.............# #^########################^#
#.........###.....#######....@..# #^#^^^^^^^^^^^^^^^^^^^^^^^^#
#.........# #.....# #.......# ###1########################
########### ####### ######### #.#
###
The left side of the level is random. Note that the temple itself is
disconnected. Entry must be made by digging. Teleportation does not
work on this level. The walls of the Mana Temple itself are
undiggable. It must be entered through the single square room at the
southwest of the Temple. Note the traps completely surrounding the
Temple. Ceiling traps replace teleportation traps in the Mana Temple.
The numeral 1 is used to indicate secret doors. Note the underscore
in the eastern center of the temple. This is the chaotic elemental
altar where the orb guardian is found (at least until he is disturbed
and moves). The standard warning about standing on altars applies -
many of the monsters are capable of speech and will sacrifice the PC.
The elemental altars can only be converted by champions of Balance or
Order, which means PCs going for an ultra ending cannot convert them
early in the game, before receiving Gaab'Baay's first quest. The
monsters in the Mana Temple are arrayed as follows:
#################
#........./.....# ############################
#.........#####.################### #^^^^^^^^^^^^^^^^^^^^^^^^^^#
#.........# #.........../.......# #^########################^#
#.........# #########.###.......# #^#ee.e.e.e.e.e........eC#^#
#.........# #...# #.......# #^#e.C.C.C.C.C.C...CCC..C#^#
########### #####.### #.......# #^#e.C.C.C.C.C.C..C###C.C#^#
#.....# #.......# #^#e.C.C.C.C.C.C.C.C#CC.C#^#
###############.##### #.......# #^1.................@CC.C#^#
#...............# #.......# #^#e.C.C.C.C.C.C.C.C#CC.C#^#
#.........#.##### ######### #^#e.C.C.C.C.C.C..C###C.C#^#
#.........#.# #^#e.C.C.C.C.C.C...CCC..C#^#
#.........#.##################### #^#ee.e.e.e.e.e........eC#^#
#.........#./.....+.............# #^########################^#
#.........###.....#######....@..# #^#^^^^^^^^^^^^^^^^^^^^^^^^#
#.........# #.....# #.......# ###1########################
########### ####### ######### #.#
###
They are: e - magebane eyes
e - magedoom eyes
C - chaos servants
C - annihilators
C - chaos wizards
@ - Nuurag-Vaarn, the Chaos Archmage
To attack the temple, the PC must travel through the trap-filled
tunnel around the temple. During this, the magebane eyes and
magedoom eyes will be draining the power points of the PC.
Classes which are dependent on power points are well advised to
bring along blessed scrolls of power. If possible, a wand of trap
detection should be saved for the Mana Temple. This is a much
faster way of detecting the traps than using the Detect Traps skill,
especially when combined with the Farsight spell or a necklace of
the eye. The faster this tunnel is traversed, the less time the
eyes have to drain the PP of the PC. The Mana Temple ranks with
the nastiest places in the game. Many players do not enter the
temple itself, instead staying in the corridor. Using this
technique, the monsters can be fought one at a time. Even so,
the chaos wizards are summoners, so the PC can still be surrounded
by summoned monsters in the corridor. The objective using this
method is to wait for Nuurag-Vaarn to exit the temple, kill him,
collect the Orb and flee.3.10.1 Nuurag-Vaarn, the Chaos Archmage
Nuurag-Vaarn is a difficult opponent, to say the least. He has a corrupting melee attack. He is very fond of casting spells, especially Darkness, Death Ray and Invisibility. Entering the Mana Temple without a means of Death Ray resistance is virtual suicide. Since the Ancient Mummy Wrapping provides both Death Ray resistance and the See Invisible intrinsic, it is a logical armor choice while in the Mana Temple. Nuurag-Vaarn is also very good at confusing the PC and is a stat drainer. He is immune to elemental attacks other than acid. He is vulnerable to humanoid slaying ammo; this is a good way to attack him if the PC can maintain a clear shot at him through all the monsters, summoned and otherwise, in the temple.
Nuurag-Vaarn's vital statistics:
You examine Nuurag-Vaarn, the invisible Chaos Archmage. Diagnosis: Level: 1, DV: 60, PV: 30, Hits: 938, Attacks: 2, Damage: 9-36. Speed: 112.
To summarize the prerequisites needed to fight Nuurag-Vaarn:
1 - Death Ray resistance - essential
2 - confusion resistance - essential
3 - light source - essential
4 - See Invisible intrinsic - recommended
5 - humanoid slaying ammo - recommended
Nuurag-Vaarn holds the Chaos Orb of Elemental Mana, greater identified as follows:
------------------ uncursed Chaos Orb of Elemental Mana {Ma+10}----------------
It is an artifact.
When used in melee combat it grants a +3 bonus to hit and causes 1d16+3 points of damage. When used as a missile it grants a +3 bonus to hit and causes 1d10+3 points of damage.
It modifies your mana attribute by +10.
(full PP, +3 Mana, corruption when 'U'sed)