Abyssos: The Fifth Circle

Abyssos: The Fifth Circle, known to players as P5, is the first turn of in Final Fantasy XIV: Endwalker.
==Story==
===Normal===
===Savage===
==Progression==
===Normal===
===Savage===
Unlike in Normal difficulty, the fight begins in the platform surrounded by green acid.
It also has a meter known as Satiety, which begins at 100 and decreases over time.
====Ruby Glow I====
The boss begins by casting Sonic Howl, dealing moderate raid-wide damage. 
The boss then casts Ruby Glow, dealing moderate raidwide damage and dividing the platform into four quadrants, as indicated by the battle log comment "The ruby keras creates cells of light!".
After the first Ruby Glow, the boss casts Topaz Stones, spawning two topaz crystals and two acid puddles, one obstacle in each quadrant. The topaz crystals then explode, killing anyone in their quadrant ("Light scatters within the cells!"), and the acid puddles grow in size. One acid puddle will be close to the center, and will not completely cover its quadrant; thus the party can avoid all the obstacles by standing in the far corner of the quadrant with the centered acid puddle.
====Caustic puddles I====
The quadrants then fade, and the boss casts Venomous Mass, a splashed tank buster that inflicts Poison and Physical Vulnerability Up. This forces a tank swap before the boss casts Toxic Crunch, a single-target physical tank buster that also inflicts Poison. Toxic Crunch ignores invulnerability if the targeted tank has Physical Vulnerability Up.
Four puddles will form, and purple orbs will spawn around them. When the puddles are surrounded by orbs, a Lively Bait will spawn from each puddle and then shortly after enrage; moreover, the party member closest to the puddle will take heavy damage. Though in principle this can be survived using a suitable Limit Break, it would be strongly preferable to prevent the Lively Bait from spawning in the first place. To do this, there need to be two party members standing on each puddle when the Lively Bait would spawn; one is insufficient to block the spawn. On the other hand, standing in the puddles inflicts a Poison debuff that falls off when the puddles resolve, so it is best to move into the puddles shortly before they resolve.
The boss then casts Venomous Mass and Toxic Crunch again.
====Ruby Glow II====
The second Ruby Glow cast only divides the platform into two separate triangles. As before, the boss casts Topaz Stones, spawning a topaz stone that will explode and kill anyone in its triangle, as well as a growing acid puddle. Before the explosion, the boss jumps to the center of the platform, faces a corner along an axis perpendicular to the middle tringle leg, and casts Double Rush. This causes the boss to rush to the corner it is facing, killing any party member in the triangle the boss rushes to. The topaz stone then explodes and the boss rushes across the stage again, knocking back every party member from the line it is rushing across.
To avoid Double Rush, the party should stack near the center, behind the boss. The boss then rushes away, but nobody is in the triangle the boss rushes to, so that attack is ineffective. If necessary, everyone should then move to avoid the exploding topaz stone, and either position themselves to be knocked back safely, or more likely use Arm's Length or Surecast to avoid the knockback entirely. All of this can be done easily while avoiding the acid puddle, which disappears shortly after the second boss dash.
The triangles then fade and the boss casts Sonic Howl.
====Ruby Glow III====
The third Ruby Glow cast again divides the platform into quadrants.
When Proto-Carbuncle casts Topaz Clusters, topaz stones spawn in the following order:
# Two stones spawn, one in each of two corners along the same diagonal.
# Two stones spawn, one in each of the two corners not yet hit.
# Three stones spawn in different corners.
# Three stones spawn in different corners.
The stones then explode in the order they spawned in. Thus:
# Two quadrants along the same diagonal will be unsafe (and the other two will be safe).
# The other two quadrants will be unsafe.
# Only the quadrant missed by the third cluster will be safe.
# Only the quadrant missed by the final cluster will be safe.
After all of the topaz stones detonate, the quadrants fade.
====An interlude====
The boss casts Venomous Mass, Toxic Crunch, and either Venom Squall or Venom Surge. Either mechanic will target the party with eight spread markers, two stack markers (one on each healer), and eight large area-of-effect damage circles that need to be baited; the difference is the order. Venom Squall is spread, bait, stack; Venom Surge is stack, bait, spread.
To survive Venom Squall or Venom Surge, it is prudent to assign each party member to a clock position around the boss, with healers at east and west. After the topaz stones detonate, the party will move as follows:
# The main tank during Topaz Clusters will move Proto-Carbuncle to the center of the platform.
# After the tank swap for Venomous Mass, the party will move to their clock spots, with the former off-tank (new main tank) taking the absolute north position (to avoid confusion between relative and absolute positioning for the rest of the party).
# The party will observe if the boss is casting Venom Squall or Venom Surge.
# If the boss is casting Venom Squall, they will remain at their clock spots for now, and otherwise they will collapse on the nearest healer.
# After the first hit resolves, they will run to the center to bait.
# Once the area-of-effect markers appear, they will return to their clock positions (Venom Surge) or the flanks (Venom Squall) to avoid the spread or stack attack, respectively.
After Venom Squall or Venom Surge resolves, Proto-Carbuncle either casts Tail to Claw or Claw to Tail. If the boss casts Tail to Claw, it attacks anyone behind it with its tail once, and then in front of it with its claws seven times in a row; otherwise it uses its claws seven times and its tail once. The seventh claw hit is slower than the first six, so it can be easily distinguished. To avoid this, the party should move either behind the boss and then in front once the seventh claw hits (for Claw to Tail) or in front of the boss and then behind it after the first and only tail attack (for Tail to Claw).
====Caustic puddles II / zero Satiety I====
As either Tail to Claw or Claw to Tail resolves, the Satiety gauge will finally reach 0. Eight blue markers and a large red teeth marker will appear on the platform, and the red marker will move around the platform, touching each blue marker exactly once. The Proto-Carbuncle will then become untargetable and jump on each of the eight blue markers in the order that the red marker touched them. At the same time, four caustic puddles spawn at cardinal positions near the center. The jump is a large area-of-effect attack that inflicts Down for the Count. At the end of these mechanics, the Proto-Carbuncle will eat a randomly selected party member with Down for the Count, if possible, and otherwise eat a randomly selected Lively Bait; this resets its Satiety gauge to 100. If it has nothing to eat, the Proto-Carbuncle will enrage by casting Acidic Slaver.
To survive this attack, the party will need to all avoid every jump, and then after the eighth jump, all but two party members will need to step into a caustic puddle (perhaps the one closest to their clock position), so as to spawn exactly one Lively Bait. The last caustic puddle will need to be absorbed by a tank with mitigation. The Proto-Carbuncle will then eat the Lively Bait before it enrages, resetting its Satiety gauge.
In order to dodge all six jumps, it helps to observe that the red teeth can only move in two patterns:
* (Turnaround case) The red teeth will move two markers clockwise, and then three markers counterclockwise; if so, it will repeat this pattern indefinitely.
* (Rotation case) The red teeth will move two markers clockwise, and then two markers clockwise again; if so, it will repeat this a total of four jumps, then turn around to the next counterclockwise marker, and then move two markers counterclockwise three times.
Therefore the party will want to always start their movement by positioning opposite where the red teeth spawn, and proceed as follows:
* Turnaround case:
*# The party will start opposite from where the red teeth spawn.
*# They will run through the center of the platform, curving slightly to avoid the third jump, as soon as the second jump resolves.
* Rotation case: The party should start one blue marker clockwise from where the red teeth spawn.
*# They will move into the marker that the red teeth spawned in as soon as the first jump begins.
*# They will run through the center of the platform.
====Ruby Glow IV====
The boss again casts Ruby Glow, dividing the platform into two triangles, followed by Topaz Stones, spawning two topaz stones in one triangle and three in the other. 
After the topaz stones spawn, Proto-Carbuncle casts Venom Pool on the two healers. Thus the healers must stack with three other party members each to mitigate this attack, but they also must stack with a topaz stone. The stone is transformed into a growing acid puddle by the venom pool. This allows the party to clear the triangle with two topaz stones, making that triangle safe to be in.
The boss then jumps to a corner and casts either Searing Ray or Raging Claw. Searing Ray targets the triangle the boss jumped into for heavy damage, while Raging Claw hits everyone not standing behind the boss in the corner. To avoid this, the party should stand in the triangle with the acid puddles, wait for the three topaz stones to explode, and then move to the triangle not containing the boss (Searing Ray) or behind the boss (Raging Claw).
The triangles then fade and the boss casts Venomous Mass and Toxic Crunch.
====Ruby Glow V====
The boss again casts Ruby Glow, dividing the platform into quadrants, followed by Topaz Stones. Two quadrants get a topaz stone and two quadrants get an acid puddle. However, unlike the previous Topaz Stones cast with this pattern, the two acid quadrants will both have a very small safe area at first, but will be completely covered after the topaz stones explode. The boss then casts Venom Squall while the topaz stones explode.
To survive, there should be four party members, including a healer, on each of the two acid puddle quadrants. As soon as the topaz stones explode, they should spread out into the topaz stone quadrant adjacent to their safe area to avoid Venom Squall, then stack up to bait the second hit, and then stack up elsewhere to bait the third hit.
====Caustic puddles III====
Four caustic puddles again form. Since the boss' Satiety gauge is nonzero, this is identical to the first appearance of caustic puddles.
After this resolves, the boss casts Tail to Claw or Claw to Tail, then Venomous Mass, then Toxic Crunch, and finally Sonic Howl.
====Ruby Glow VI====
The boss casts Ruby Glow, creating quadrants, followed by Topaz Stones, which creates two or three topaz stones in each quadrant. It then casts Venom Pool followed by Double Rush.
To survive this requires no new ideas: the party should move to a quadrant with two topaz stones, turn them into acid puddles using the Venom Pools, go behind the boss after it jumps, and then use Arm's Length or Surecast to block the Double Rush.
====Enrage====
The boss repeats its attacks from here, in order: Venomous Mass, Toxic Crunch, Sonic Howl, Venom Squall or Venom Surge, Tail to Claw or Claw to Tail, Venomous Mass, and finally Toxic Crunch. The boss then casts Sonic Shatter, a heavy raid-wide attack which increases in damage each time it is cast. After five casts of Sonic Shatter, the boss reaches zero Satiety and casts Acidic Slaver, instantly killing the party.
==Musical themes==
The theme of the Fifth Circle is "Silent Scream", an instrumental mix of "Scream", the main boss theme of Abyssos.