TzKal-Zuk
Introduction
TzKal-Zuk is the general of the Ful Front of the Elder God Wars. This encounter is the third version of the Fight Caves/Fight Kiln, in that you fight waves of enemies before taking on the main boss.
Presets and Relics
Preset Notes
⬥ If any obsidian armour piece is used, it is also beneficial to donate Tokkul to the coffer at the Fight Cauldron; doing so will provide an extra 10% damage reduction for 20 minutes per 15,000 Tokkul donated, which can be stacked up to 3 times for a maximum duration of an hour.*
⬥ Powder of Penance 
is used before starting the hour.
The Fight
This encounter has 17 waves of enemies, and then the final boss, TzKal-Zuk. Normal mode has checkpoints after waves 5, 10, 15, and 17. Hard mode has one checkpoint after wave 17. The arena has some ledges in it that can be used to lure/safespot various mobs.
General Wave Safespot
*1. Start at the southeast corner
a. There is a lava geyser here which can damage you, but isn’t much of a worry if you use animate dead
b. You can move as far south as you can to attack mobs over the ledge
c. You can move to the east to dodge the wall of fire in hardmode
- There should only be 1-2 mobs that can attack you at a time.
a. Kill them and move out to let some more mobs find you. Move back in once they are untrapped
- Repeat until the wave is cleared*
Normal Waves (1-3, 7-8, 12-13) and Igneous Waves (4, 9, 14)
Waves 1-3
⬥ Wave 1: 
at 10 seconds Kih will spawn south and southeast, kill them immediately.
⬥ Wave 2: 
focus the Xil x2 > 
Kih > Yt-Mejkot.
⬥ Wave 3: Xil > Kih > Yt-Mejkot.
Waves 7-8
⬥ Wave 7: Kih > Yt-Mejkot > Tok-Xil > Mej > -Xil.
⬥ Wave 8: Focus Mej, > Yt-Mejkot > Tok-Xil > Xil. Tok-Xil takes priority over anything else when safely attackable.
Waves 12-13
⬥ Wave 12: 
Mej > Tok-Xil > Kih x2 > Tok-Xil > Mej x2 > NE Ket-Zek > Mej > NW Ket-Zek.
⬥ Wave 13: Ket-Zek > Tok-Xil > Mej > Tok-Xil > Ket-Zek > Mej, NE Ket-Zek > Mej > NW Ket-Zek.
Igneous Waves 4, 9, 14
⬥ 3 Large Igneous variants of mobs will spawn along with many normal versions of that mob
• Igneous TzekHaar-Hur
⬩ Weaken by stunning, then kill normally.
• Igneous TzekHaar-Xil
⬩ Weaken by using a threshold or ultimate ability, then kill normally.
• Igneous TzekHaar-Mej
⬩ Weaken by standing in it's shield dome, then kill normally.
• Only the 3 Igneous variants need to be killed. The rest of the mobs can be ignored.
⬩ After killing the last Igneous mob of the wave, an extra action button will appear on your screen. Click that and attack TzKal-Zuk until you deal 50,000 damage to him.
Note: If you fail to deal 50,000 damage to TzKal-Zuk, the phase repeats itself and you must do the remainder of the 50,000 damage to trigger the next phase
Challenge Waves (5, 10, 15)
These waves are challenges for the player. They must be completed successfully to achieve a flawless run which unlocks hardmode, or in hardmode it grants the ability to make the tribrid cape.
Wave 5
⬥ You must kill the 5 Volatile TzekHaar-Hur before the bar fills above their head.
• Failure to do so will result in large typeless hits for each one left alive.
Wave 10
⬥ You must kill the Unbreakable TzekHaar-Ket before the bar fills above its head.
• Only hits that deal 3000+ damage will hurt this mob.
Wave 15
⬥ You must survive several attacks from three Fatal TzekHaar-Yt-Hurkots. Each one attacks with a different combat style, and for a flawless run you must not take damage.
• Barricade 
works for this.
Jad Waves (6, 11, 16)
Wave 6
⬥ This is the first wave with a Jad. kill it asap then focus on the other mobs.
Waves 11 and 16
⬥ Wave 11 has 2 Jads and various mobs.
⬥ Wave 16 has 3 Jads but no other mobs.
Jad Wave Safespot
1. *Start at the northwest corner and kill Jad 1
-
Clear out the extra mobs as needed (Wave 11)
-
Move south to allow Jad 2 to attack you (yellow arrow)
a. Jad 3 should get stuck behind Jad 2 and be unable to attack
b. For wave 11, Jad 2 doesn't exist so ignore this step
- Once Jad 2 is dead, move towards Jad 3 and kill it*
TzekHaar-Aken
Wave 17
⬥ This is the last enemy before fighting TzKal-Zuk. His head will appear for about 40 seconds when the wave starts. He has a lot of tentacles (Mage and Ranged) which will constantly attack dealing small damage.
• After 40 seconds, his head will submerge for about 50 seconds, in which time you can kill some of the tentacles and use defensive abilities to mitigate some damage. You do not need to kill any tentacles finish the phase. Just the head needs to die.
• He has a mechanic that shoots a blob to your location that drains your adrenaline by 10% immediately and makes you gain 50% reduced adrenaline for a short time.
⬩ When his head is exposed, he only fires 1 blob at a time.
⬩ When he submerges, he fires blobs that expand into a 5x5 X shape at your players location. These can be dodge by moving out of the way.
TzKal-Zuk
He primarily attacks with melee in melee distance, otherwise with magic.
Mechanics:
Zuk performs a mechanic after every 3 auto attacks in normal mode. The mechanics appear in order as follows, and will repeat once all mechanics have happened.
Note: Zuk will skip the first 3 auto attacks and go into the Geothermal Burn mechanic as soon as the encounter starts. In addition, when Zuk hits 100k lifepoints, he will restart his attack rotation, starting with the Geothermal Burn.
⬥ Geothermal Burn: Zuk shouts You will break beneath me! and applies a magic bleed that lasts for 20 seconds.
• The bleed can be stopped by using Freedom 
.
⬥ Sear: Zuk shouts Sear! or Suffer! and hits you with a melee hit and 2 magic hits, and lowers your constitution level.
• You need to travel 15 total tiles to stop the hp drain, and drink super restores to clear the debuff.
• This mechanic can be mostly negated instantly by using (Surge 
as soon as Zuk does the spec, which will be his 4th attack after the last spec, and running back to where you started.
⬥ Quake: Zuk shouts Tremble before me! or Fall before my might! and causes the floor to crack in small areas around him that deal a lot of damage and apply an escalating magic bleed if stood in.
• This mechanic can be mostly negated instantly by using (Surge as soon as Zuk does the spec, which will be his 4th attack after the last spec, and attacking from your new location.
• Getting hit by any of the eruptions from the ground fissures will apply the same magic bleed from Geothermal Burn. However, your Freedom will still be on cooldown.
⬥ Empowered Magic: Zuk shouts Die! Begone! or Ful's power flows through me! and shoots a projectile at you that deals high soft-typeless damage.
• You can use Disruption shield 
or Resonance 
to take 0 damage from this.
⬥ Igneous Rain: Zuk shouts Flames consume you! or Burn! and jump to the middle of the room, becoming immune to attacks, stunning and dragging you, and covering all but one section of the arena with fire that ramps up damage the longer you stand in it.
• You can use Surge and Bladed Dive 
to get to the safe part of the arena, where an Igneous mob will be waiting for you to kill.
⬩ Kill these the same way as in waves 4, 9, and 14. Use the extra action button to interrupt the mechanic. If you fail to interrupt it, it will instakill you.
It should be noted that Zuk will skip the first 3 auto attacks and go into the Geothermal Burn mechanic as soon as the encounter starts. In addition, when Zuk hits 100k lifepoints, he will restart his attack rotation, starting with the Geothermal Burn.
Example Kills
Alt1 TzKal-Zuk Helper
Voice guidance throughout the kill
This tool reads your screen, and based on certain lines of dialogue in your chatbox, will trigger and play voice lines during the kill to let you know about upcoming mechanics and what to do for them.
Disclaimer: Alt1 is a third party tool, and while generally safe to use, is still recommended to be installed and used at your own risk.