The Sil'dihn Subterrane

The Sil'dihn Subterrane and Another Sil'dihn Subterrane are the first set of in Final Fantasy XIV, introduced in patch 6.25 of the Endwalker expansion for level 90.
==Story==
===Variant===
===Criterion===
===Savage===
==Objective==
=== Variant===
* Clear the Sil'dihn Subterrane
** The party will need to escort NPC Nanamo Ul Namo through one of three potential paths and defeat the final boss present at the end.
===Criterion/Savage===
* Clear the refuge of the wise
* Defeat the silkie
* Clear the refuge of the powerful
* Defeat the gladiator of Sil'dih
* Defeat Shadowcaster Zeless Gah
== Progression==
===Variant===
====Thresholds Three====
The immediate starting location of the instance. Three doors are present, of which only one can be opened. Nanamo will express a preference for one of the three doors, before asking the party to make a decision. Once a decision has been made, the party will be locked into that path for the rest of the instance.
====Left Path====
===== Irrigation Ducts=====
Heading through the left door, players will encounter three groups of mobs with Nanamo. After progressing past the third group, they will come across an interactable cistern switch. Players can choose to interact with the switch or simply press onwards, however once a choice is made it will lock in and affect the mechanics of the upcoming boss.
======Silt Pump ======
At the Silt Pump you will confront the midboss, Geryon the Steer. Geryon is the midboss for all paths in the instance, however the mechanics of the ability "Subterranean Shudder" will change depending on the path taken and choices made. For brevity's sake, Geryon's common mechanics will be listed in this section, while his path and choice specific mechanics will be detailed in the appropriate sections. 
* Colossal Strike: Tankbuster
*Colossal Slam: 60 degree conal cleave in front of the boss.
*Colossal Swing: 180 degree cleave in front of the boss
*Exploding Catapult: Deals roomwide damage and summons barrels that will explode after a set amount of time. Red barrels explode in point-blank AoEs, blue barrels explode in dynamo AoEs.
*Colossal Launch: Deals roomwide damage and flips any available barrrels to the opposite color.
*Colossal Charge: Line AoE through the centre of the arena. Any barrels or players in the path of the AoE will be knocked towards the indicated direction.
*Gigantomill: The boss performs a rotating cross shaped cleave centered on itself.
*Shockwave: A room wide AoE that also causes knockback from the vertical centre of the arena.
*Subterranean Shudder: The effect of this ability will change depending on whether or not the player activated the cistern switch prior to arriving at the Silt Pump. If it was activated, the ability will be a knockback from a specific point of the arena. It will be paired with three red barrels and one blue barrel apearing on the arena so attempt to be pushed back into the blue barrel or use knockback resistance. If the switch was not activated, the ability will instead cause mud puddle aoes to form on the arena, which can be paired with Shockwave.
=====Spring's Passage=====
After defeating Geryon you will come across a forking path, however one the branches will be blocked randomly, and you will be forced down the other route. This does not affect any dungeon outcomes. Defeat all the mobs you encounter before reaching the Malachite Portico.
======Malachite Portico======
This section consists of a puzzle, where you must collect one each of the yellow and green sacks and place them on the pedestals. Opening the door by selecting any of the sacks will lead to a few mobs surrounded by patches of flowers. Killing the mobs will open the path to the Groundwater Intake, however if the player runs through the flower patches, they will trigger a visual effect and change the mechanics of the upcoming boss.
====== Shaded Solace======
Selecting the correct sacks in the Malachite Portico (the northeasetern most green sack and southeasternmost yellow sack) will activate a portal in the centre of the room that will transport you to Shaded Solace. Here you encounter some golems and snurbles before Nanamo will head towards the gate. Before meeting up with her, there will be a door on the west side of the room that can be opened to reveal a jar.
===== Groundwater Intake=====
======Forgotten Forcourt======
Here you will face the final boss of this path; the Silkie.
* Total Wash: Roomwide AoE. First use will create a persistent AoE on the borders shrinking the effective area. 
* Squeaky Left/Right: The boss will perform two 120 degree conal cleaves to it's front before performing a 240 degree cleave extending the previous frontal cone in the indicated direction.
*Carpet Beater: Tankbuster
* Chilling Suds: Infuses the tail pom with ice aether and grants the boss Chilling Suds. Unleashes a plus shaped AoE cleave oriented in the direction the silkie faces.
* Bracing Suds: Infuses the tail pom with wind aether and grants the boss Bracing Suds. Unleashes a dynamo AoE centred on the boss.
* Soap's Up: Triggers the effect of the aether infused into the tail pom.
* Slippery Soap: A line AoE that will cause the boss to travel to one of the four quadrants of the arena before trigerring the tail pom's Sud effect.
*Spot Remover: Sets off a number of AoEs that leave persisting water puddles behind which inflict Dropsy.
*Dustblaster: Knockback from centre of arena
*Fresh Puff (2): Summons three pom brooms. If the pom brooms are hit by Squeaky Left/Right, they will become infused with the same aether type as the pom, including no aether .
* Soaping Spree: Triggers all active Sud effects.
* Route dependant mechanics: These abilities and mechanics change depending on actions players have taken throughout the path.
** Fresh Puff (1): This ability will be used if players open the door in the Malachite Portico -
*** If players have triggered all of the flower fields, this mechanic will have multiple dust puddles appear. Brooms will appear at one side of the arena and will subsequently begin travelling to the other side. The brooms will deal damage if they touch players. When a broom reaches a dust patch, it will trigger an AoE that also delayss the broom from moving forward.
*** If players have avoided the flowers, this mechanic will have multiple brooms appear at one end of the arena. The brooms will travel across the arena by making delayed AoEs. In this variation, the brooms themselves do not deal damage.
**Eastern Ewer: This ability will be used if players activate the teleporter in the Malachite Portico and opened the door to the supply closet. This mechanic will summon various water ewers at one side of the arena which will travel across to the other side in random order, dealing damage if they contact players.
**Wash Out: If players did not open the door to the supply closet, this ability will summon a giant water spout that will knockback players the entire length of the arena.
======Sunlit Garden ======
Defeating the Silkie will allow you to progress to the Sunlit Garden, where the exit awaits. Entries 1 - 4 of the dungeon log can be unlocked via this path, depending on which mechanics have been triggered for the silkie.
==== Middle Path====
=====Cistern System=====
Clear the three sets of mobs that are on this path. After the first set, players will need to activate a switch to raise the water level and employ a bridge to continue. After defeating the third set of mobs, players will come across a door with a mechanical valve. Interacting with the valve will allow you to turn it either left or right, which will affect upcoming mechanics.
======Sifting Site ======
At the Sifting Site you will confront Geryon the Steer.
*Subterranean Shudder: The effect of this ability will depend on whether the player has turned the valve left or right on the door prior to encountering the boss. Turning the valve left will cause this ability to activate wind turbines on the sides of the arena that will pull players 3/4 of the arena length towards them. Turning the valve right will cause this ability to activate 2 conveyor belts with giant boulders. These boulders will roll through one lane of the arena each.
===== Quarter of Rule=====
After defeating Geryon, there will be a fork in the path, but one of the branches will be randomly blocked by rubble.
======The Sultan's Table======
The left path will bring you through a dining room and into a large central chamber. Climbing the stairs, Nanamo will notice a flag before a group of Sil'dihn snakes spawn. Defeat them to continue on to the main path.
======Royal Bedchambers======
The right path will bring you into a bedroom. Nanamo will notice flag before a group of enemies spawn. Defeat them to continue on to the main path.
======Audience Chamber======
Arriving from either branch will bring you to the Throne room. A group of Sil'dihn Dullahans will spawn soon after. Defeat them to cause a hidden path at the back of the room to be revealed.
=====Hidden Halls =====
Continuing on from the audience chamber, players will come across a puzzle. They will need to place two of the four available symbols into the scales and the activate them to complete it. Choosing the wrong symbols, or simply activating the scales before both selecting two symbols will cause 3 Sil'dihn golems to spawn. Defeat them to open the door to the north. Here they will be prompted to activate one of two levers to cross a small chasm before the final boss.
======Prosperity======
To enter Prosperity, players will need to correctly solve the puzzle in Hidden Halls, the solution of which is concealed through the random paths from the Quarter of Rule. This will activate a hidden teleporter that will lead to the treasure vault. A note left in the north of the room will contains some clues for the other paths. After dispatching some enemies, players will be prompted to interact with one of the statues of the Traders to dispel a barrier and allow further progression. 
======Cornice of Favour======
Here you will face the final boss of this path; the Gladiator of Sil'dih.
* Flash of Steel: Raidwide damage
* Ring of Might: Boss returns to the centre of the arena and 3 rings will appear with a charge bar. The amount of charge will determine the size of the initial pointblank AoE corresponding to the rings. This inital AoE will be followed up with a dynamo AoE affecting the previously untargeted part of the arena.
* Rush of Might: Boss rushes to a corner of the arena and a line marker with 3 other indentations will appear with a charge bar. The amount of charge will determine the distance the boss will rush corresponding to the indentations. The boss will perform a 180 degree full room cleave in front of it before performing another 180 degree cleave behind it.
* Sculptor's Passion: Line Cleave AoE in front of the boss
* Mighty Smite: Tankbuster
* Wrath of Ruin: Summons two sets of two lines of orbs that cover adjacent sides of the arena. The orbs will shoot line AoEs in a cross pattern, and detonate in sequence.
* Sundered Remains: Summons nine AoEs in sequence that will cover the arena.
* Route Dependant Mechanics - These mechanics change depending on actions players have taken throughout the path:
** Shattering Steel - raidwide AoE that deals massive damage. Utilized if players fail the scale puzzle.
*** If the left lever was pulled before the arena, 4 proximity AoEs will spawn and detonate in sequence. Each AoE will leave behind a boulder, three of which will be cracked. The cracked boulders will break when Shattering Steel finishes casting, the uncracked boulder will shield players if they Line-of-Sight the boss.
*** If the right lever was pulled before the arena, 4 persisting whirlwind AoEs will spawn that will knock players into the air and deal damage. To avoid Shattering Steel, players will need to step into the gust AoE with the arrow marker just before the cast bar finishes.
** Hateful Visage - Summons untargetable Hateful Visages for mechanics. Used if the players have entered via Prosperity:
*** If players deactivate the statue of Nald, 4 sets of visages will spawn to shoot AoEs that cover a quadrant of the arena each. One of the quadrants will not be targeted and thus be safe.
*** If players deactivate the statue of Thal, 2 visages will spawn in the back corners that will shoot rotating line AoEs.
Upon defeat, the exit will spawn at the north of the arena. Entries 8 - 11 of the dungeon log can be unlocked via this path, depending on which mechanics have been triggered for the gladiator.
====Right Path====
=====Sanitation Sluices=====
Throughout this first section, players will fight three sets of mobs. In the third set of mobs, there will be morbol-type enemy called an Aqueduct Ameretat . Killing this mob first in the final group will affect mechanics for Geryon.
======Settling Basin ======
At the Settling Basin you will confront Geryon the Steer.
*Subterranean Shudder: The effect of this ability will change depending on whether or not the ceruleum pipe just before the bosss bursts open or not. The pipe will burst if the Aqueduct Ameretat enemy in the Sanitation Sluices is killed first in the group of enemies it is part of. If the pipe is broken, the ability will cause two adjacent squares on the arena to be covered by a persistent AoE puddle. If the pipe remains intact, the ability will instead cause all four squares of the arena to alternately blow up in 2 sets of diagonals.
=====Flame's Fork=====
You will come across a winch that will allow you to either progress left or right. The left-hand path contains 2 sets of mobs before linking to the main path. The right-hand path contains some golems and a family of Drakes of various sizes before it also links to the main path.
======Ceremonial Stores======
To access the Ceremonial Stores, players will need to kill the Drakes in the right-hand path of Flame's Fork from largest to smallest. This will result in a secret path opening instead of the route to the main path. In the stores you will confront some ghost enemies. Kill them and the path to the Trader's Return will open. There will also be an incense burner on the right hand side of the room that players can interact with, but only before Nanamo leaves the area.
=====The Trader's Return=====
Continuing on the main path will bring you to a door. When you can, interact with the text on the door and you will be prompted to answer a riddle. Answering with "Spark" will result in you attacking the door to progress, while answering "Flame" will cause the door to open.
======Eternal Ease======
In the tomb you will see a sarcophagus. Interact with it to face the final boss of this path; Shadowcaster Zeless Gah.
* Show of Might: Raidwide damage
* Infern Brand (1): Summons 4 sparks of flame that will detonate in larger AoEs.
* Infern Brand (2): Summons 4 Infern Brands across the arena that will shoot persisting tripwire AoEs in alternating directions. Crossing one of these AoEs will detnoate the player for large damage.
* Firesteel Fracture: Tankbuster. A targeted 60 degree cleave
* Cryptic Portal: Can be used with Infern Brand (1) to teleport the sparks to different locations. The teleport locations can be changed if the markers rotate.
* Pure Fire: AoEs that will spawn under players. Move out of the AoE to avoid damage.
* Cast Shadow: Summons alternating conal AoEs.
* Route Dependant Mechanics: These mechanics change depending on actions players have taken throughout the path.
** Infern Gale: 4 brands will be staked in the arena in a square. If players answer the door riddle incorrectly, then this mechanic will have one of the brands knock back players.
** Infern Well: 4 brands will be staked in the arena in a square. If players arrive via the Ceremonial Stores, then this mechanic will have one of the brands draw in players and then subsequently explode in a point-blank AoE.
** Infern Ward: If players answer the door riddle correctly, this mechanic will be used. The boss will occasionally summon Arcane Fonts at the edge of the arena. The Fonts will perfom a line AoE covering the entire row or column of the arena they are in.
Upon defeat, the exit will spawn at the north of the arena. Entries 5 - 7 of the dungeon log can be unlocked via this path, depending on which mechanics have been triggered for the Shadowcaster.
====Hidden Path====
To access the hidden path, players must go through the right path and enter the Ceremonial Stores. After defeating the enemies here, they will need to quickly interact with the incense burner on the right side of the room before Nanamo leaves. At Eternal Ease, instead of interacting with the coffin, players will need to target it instead and subsequently perform the emotes /bow, /respect, /vpose, and /kneel in that order. If done correctly, this will prompt Nanamo to light the incense burner, and subsequently open a hidden door to the north of the room.
=====Friendship's Testament=====
======Cold Arms' Quietus======
Here you will face the hidden final boss; the Thorne Knight.
* Cogwheel: Raidwide damage
* Spring to Life: Channels aether into the mammets and cannons lining the walls of the arena, activating them to shoot line aoes. only to walls will be activated, and whether it is the mammets or cannons activated on each side depends on the arms supplying aether.
* Fore Honor: Cleaves the entire arena 180 degrees in the direction the Knight is facing.
* Slashburn: Shoots a line AoE the width of the Knight's target ring to it's right, while also preparing two 90 degree conal AoEs to the left angled slightly away from each other. A variation of this technique will cause it arms to switch sides, changing the AoEs right before they go off. The arms will remain switched until the next time the variation is used.
* Signal Flare: Causes 3 sets of 3 circle AoEs to appear one after the other before detonating in sequence.
* Blistering Blow: Tankbuster
* Blaze of Glory: Summons two balls of fire that will explode in a cross pattern extending to the sides of the arena.
After defeating the Knight, the platform at the north of the arena will activate, teleporting players to the entrance of a vault where the gold chest sits. Inside the vault, Nanamo will remark at the findings and thank the players for their escort. This will unlock entry 12 of the dungeon log. First time completion of this route will unlock a follow-up quest in Ul'dah, and subsequntly add the story to New Game +.
===Criterion===
==Enemies==
;Left Path
* Aqueduct Bat
* Aqueduct Uragnite
* Aqueduct Pudding
* Aqueduct Eft
* Aqueduct Mossling
* Geryon the Steer
* Aqueduct Fluturini
* Aqueduct Goobbue
* Aqueduct Adamantoise
* Aqueduct Leafkin
* Aqueduct Genomos
* Aqueduct Oqdan
* Aqueduct Leshy
* Aqueduct Golem
* Aqueduct Snurble
* Soapy Sidekick: Silkie
;Center Path
* Water Sprite 
* Aqueduct Focalor
* Aqueduct Sarcosuchus
* Aqueduct Elbst
* Aqueduct Gelatin
* Geryon the Steer
* Sil'dihn Python
* Sil'dihn Dhruva
* Sil'dihn Urolith
* Sil'dihn Dullahan
* Sil'dihn Golem
* Sil'dihn Hollow
* Sil'dihn Visage
* Lifeless Legacy: Gladiator of Sil'dih
;Right Path
* Aqueduct Goosefish
* Aqueduct Wamoura
* Aqueduct Gigantoad
* Aqueduct Slug
* Aqueduct Hecteyes
* Aqueduct Ameretat
* Geryon the Steer
* Forgotten Cliffmole
* Forgotten Sabotender
* Forgotten Campeador
* Forgotten Phoebad
* Forgotten Spider
* Forgotten Dhara
* Forgotten Drakefather
* Forgotten Drakemother
* Forgotten Drakebrother
* Forgotten Drakesister
* Forgotten Drakeling
* Forgotten Revenant
* Forgotten Wraith
* Undead Shadowcaster: Zeless Gah
* Armed Automaton: Thorne Knight
==Musical themes==
The theme for the Variant version of the dungeon is "To the Sun (From Astral to Umbral)", an arrangement of the various Thanalan field themes. The theme for the Criterion and Savage version is an arrangement of "Twilight over Thanalan" known as "Desert Sun". "On Blade's Edge" plays as the midboss theme for the variant dungeon, while "Finality" plays for all possible final bosses across the dungeons with the exception of the Thorne Knight, during which the song "Heroes Forge Ahead" plays.
The Sil'dihn Subterrane
The Sil'dihn Subterrane