The Final Nail
The Final Nail dungeon is the Transmuter gold challenge. The level has the Shifting Passages tileset, however the layout is closely similar to that of the Demonic Library and there are no scripted wall spawns.
The dungeon always seems to spawn the same five glyphs: IMAWAL, ENDISWAL, WONAFYT, BYSSEPS and BURNDAYRAZ. There are regular shops. There are no subdungeons. There is one fixed altar, dedicated to Taurog.
This dungeon will host all unlocked monsters. The monsters on this level have high stats (roughly 40% above nominal Attack and Health, which puts difficulty just above Vicious).
The boss is Crusher ( Golem icon, Attack 300, Health 222, Fast Regen, Cowardly, Retaliate: Fireball, Death Protection (3) ).
Initially Crusher looks quite intimidating thanks to his high damage, coupled with his Retaliate:Fireball and 3 layers of death protection. However, his weakness is his low health. Luckily, Taurog offers Death Protections, which circumvent his high damage, as well as boosts damage, which reduces the number of hits needed. Crusher is best taken on when his health can be depleted in two strikes, and his first hit can be survived. Given his damage and health, to achieve this, you will need at least 111 damage, and at least 105 Health. Assuming you do not find any items in stores that help you... if you play as a Human, the bottleneck will be the Health, for which you need to be Level 9 (you only have 104 Health on level 8); if you play as a Dwarf, the bottleneck will be the damage you deal, and you need to be Level 8 to be able to deal exactly 111 damage assuming both SPIRIT SWORD and BYSSEPS is triggered. The recommended approach breaks down the level into 3 parts:
1. Pre-Taurog: the objective is to gain as much bonus experience as possible, killing the fewest possible monsters in the process, while triggering several conversions. Especially preserve monsters with magical attacks. Do not convert any glyphs. Feel free to explore as much as 75% of the map via LEMMISI or regular exploration. Rack up bonus experience using WONAFYT, IMAWAL and going for higher-level kills via your SPIRIT SWORD. It is possible to kill less than 10 monsters to reach level 6. It is fine to leave glyphs on the floor if not yet needed (in fact, especially if you're playing as a Dwarf, consider leaving BURNDAYRAZ on the floor until the very end game). A good time to finish this phase is when you are level 6 and you have slowed all monsters at or below level 6.
2. Taurog, pre-boss: start worshipping Taurog and use your initial piety to grab Skullpicker. Additional SPIRIT SWORD uses can be triggered by glyph conversions. Use up all of your glyphs, except BURNDAYRAZ and ENDISWAL, for this purpose, continuing to go for higher-level kills. Ask for Taurog's remaining boons, you can safely leave them on the floor for the time being. The 5% bonus damage from each boon offsets the loss of SPIRIT SWORD base damage. A good time to finish this phase and start the boss fight is when you meet the requirements to tackle Crusher (spiked damage 111+, health 105+), which assumes you are Level 8 (if playing as a Dwarf) or Level 9 (if playing as a Human).
3. Boss fight: use ENDISWAL to get 65% Physical Resist for the first strike. Gain a layer of Death Protection latest for the second srike. It should not take more than 2 hits to deplete Crusher's health. Strike him twice, the second one should remove your death protection as well as Crusher's first layer. Get another Unstoppable Fury and strike Crusher again to remove the second death protection. Then replenish your health via your potions, and cast BURNDAYRAZ to take out the last Death Protection (and inflict burning) on Crusher. Lastly, strike another monster to kill him via the Burning damage. Crusher's damage progresses as follows: 300->255->217->184, so without significant resistances you will not survive even his last form's attack. However, as of the third form, a retaliation should be survivable (for a Dwarf, even earlier).
If you're playing as a Dwarf, you will need to use both BYSSEPS and BURNDAYRAZ during the boss fight, plus you'll need all of Taurog's gear, and several potions, so you might run into some inventory management issues. You can delay picking up the last pieces of Taurog's gear right until the point where you need the Death Protection, which gives you enough inventory to manage your glyphs. However, it's best if you kept BURNDAYRAZ (or your potions) on the floor, otherwise you'll have a bit of a space problem. For example, if playing as a Dwarf, you could: 1) repeatedly cast ENDISWAL to reach 65% resistances; convert ENDISWAL and cast BYSSEPS to trigger both SPIRIT SWORD and Might for your first strike; 2) cast (and then convert) BYSSEPS to trigger both SPIRIT SWORD and Might for your second strike; 3) pick up health potions as needed and drink them to restore health, and Mana potions to give you 6 Mana; 4) pick up BURNDAYRAZ to blast the boss.
The Orc Transmuter plays much like the Human. He can trigger SPIRIT SWORD a bit more often and has better early-game damage, at the expense of a bit of late-game spike damage, which should nevertheless still be sufficient to kill the boss.