Timeless Wallow is the Gilded dungeon in The Parch for Night Market. Gilded B'Kyfxi is the only boss.
To enter, you need the Windglass ( ) and both The Parch Gilded Key fragments from Argent Ash Titan and Argent Ozezan the Inferno . Defeating Gilded B'Kyfxi gives one Opulent key fragment for Opulent Ordeal.
Three elite adds spawning throughout the fight, and then a second phase starting at 45%. Focus the adds, avoid AoEs, and outheal Sapping Burst.
Keep B'Kyfxi faced away for Mind Blast , keep killing Malicious Spheres before they charge, and block, dodge roll, or don't get hit by Tentacles . At 85%, 70%, and 55%, B'Kyfxi pauses to summon a Bone Wyrm with skeletons, so focus the Bone Wyrm, interrupt the archers, and avoid Cold Snap . At 45%, she gains access to Grave Darkness , Immutable Strike , and Sapping Burst , but doesn't summon Bone Wyrms anymore.
Cleave
B'Kyfxi's light attacks cleave in front of her instead of only hitting the tank. If the boss is turned into the group, anyone standing in front gets damaged.
What to do
Before 45%, tank keeps the boss faced toward the center so chaining all the skeletons is easier. Group stays behind the boss on the outer edge. After Shadow Form, flip the positioning because there are no more skeletons and DDs need the room to kite Grave Darkness.
Orbs that stun when not killed in time
Malicious Spheres roam around the room and can be killed. If a player walks into one, it explodes, stuns, and sends more beads outward. If left alone long enough, the sphere will eventually charge on its own.
What to do
Kill them. If one does charge, break free and outheal the damage.
AoEs
Tentacles swipe at players and leave extra AoEs in the room.
What to do
Block, dodge roll, or get out of the AoEs.
Elite add at 85%, 70%, and 55%
At 85%, 70%, and 55%, B'Kyfxi summons one Bone Wyrm plus skeletons, including 2 archers with interruptible channels and melee skeletons.
What to do
Focus the Bone Wyrm and interrupt the archers.
Cone AoE with gaps
The Bone Wyrm uses Cold Snap, a cone AoE with gaps inside it.
What to do
Block, dodge roll, or stand inside the gaps.
Heavy attack which spawns adds
The Bone Wyrm's heavy attack projectile spawns 2 scarabs on the tank's location. If they get too close to you, they shred your armor.
What to do
Tank should dodge the hit and kite the scarabs away.
Second phase
At 45%, B'Kyfxi enters Shadow Form and now uses Grave Darkness , Immutable Strike , and Sapping Burst .
Kite
Grave Darkness targets the 2 closest players, excluding the tank. It can be blocked or dodge rolled, but its damage ramps up over time, so kite it left to right and dodge roll whenever you have to move through it after running out of space.
What to do
Kite it away from the group.
Heavy attack
Immutable Strike is a heavy attack projectile that cannot be dodge rolled and can be extremely deadly if a Malicious Sphere stuns you right before it.
What to do
Block.
Healing debuff
Sapping Burst lowers your health, doubles your Ultimate cost, and then applies a healing debuff. Tanks should use damage shields because any damage that hits real health while Sapping Burst is on you is extremely costly to outheal.
What to do
Heal it immediately. Tanks should use damage shields so any other damage does not hit real health while Sapping Burst is up.
Defeating Gilded B'Kyfxi will grant you the following buff:
Abyssal tendrils join from the void! When an abyssal tendril spawns, three Pearls will appear. Each Pearl you collect shields you from 33% of incoming damage. The tendrils will attack any enemies near them and heal you when you stand near where they spawn. Sand Swipe only lasts 15 minutes and only takes effect within the bounds of the Night Market.
Footage from the dungeon is below.