Machinist DPS Unending Coil of Bahamut (Ultimate) — Endwalker 6.2

The Unending Coil of Bahamut is the first Ultimate released in Final Fantasy XIV: Stormblood. The fight syncs you down to level 70 in an attempt to keep the difficulty of the fight equal to what it was on release. While it does not do a great job of that, it does remove certain skills and abilities that we gained in Shadowbringers and Endwalker. The encounter is split into five phases: Twintania, Nael deus Darnus, Bahamut Prime, Twintania + Nael deus Darnus, and Golden Bahamut. The fight in its entirety is 19 minutes long. This guide assumes a basic understanding of how Machinist works, while outlining specific optimization due to phasing and AoE situations.

With so many gearing options and different phase pushes, true BiS does not exist. The most important thing that will affect your DPS is ensuring you have the Shadowbringers 535 relic. This weapon allows you to maximize your stats with a load out of Relic substats with 127 CRIT/123 DH/127 DET/90 SKSP. Every other piece of gear should be at a minimum of item level 470 to ensure it syncs down to max stats. Food for the fight will just be whatever the current max level food with Critical Hit on it is.

There are three differences at level 70 that should be thought about when figuring out how to maximize potency gains.

1. Hot Shot: 300 potency compared to Air Anchor, which is normally 700 potency. The main thing to consider is that buff alignment matters very little (if anything, it is better to use it outside of buffs) for Hot Shot. With only 300 potency, it now does less damage than Slug Shot. The expected potency is 460 when you include the Battery gain, so it is still worth using and should be used as many times as possible.
2. Rook Autoturret: 100 Battery is now 800 potency, and there is no wind-up animation on summon. Rook should still be used within buff windows, but you no longer want to use it before buffs come up. At 100 battery, Rook will attack for exactly 15s from pressing the button to give you an idea of when you would need to summon it to get Rook Overdrive in buffs.
3. Gauss Round and Ricochet no longer have three charges; they have been reduced to two. It is much harder to avoid overcapping your charges inside of Hypercharge, and this also limits which openers you can use. The third, fourth, and five GCD openers all work at 70. The General Purpose opener (sixth GCD) will force an overcap on Gauss and Rico. If you go into Hypercharge at zero stacks on both, but the cooldown on Gauss or Rico is seven seconds or less, it will overcap by the end of the ability's usage, even with weaving between every Heat Blast. Sometimes, this may be unavoidable, and it is just something you would need to deal with. It grants a minimal loss (if any), but it is mentioned to let you know it may not be a mistake on your end.

This phase is extremely straightforward, and there is not much to cover. Pots are viable or can be shifted to Nael for prog. As physical ranged, you will most likely be forced to handle the Liquid Hell mechanic. Hatch is random on DPS players, so you will also be handling those. After Liquid Hells, it is good practice to get in range of healers to catch some heals. Second Wind is your friend. The most important thing to remember for Hatch is how Neurolinks work. Standing in them will give you a 90% damage down to every damage action you use. You can mitigate this by using a GCD just before stepping into the Neurolink, taking the Hatch, and stepping out of the Neurolink all before your next GCD. The only time this is probably not easy to make consistent is during the Hypercharge window.

Twintania usually dies around 2:25 (or earlier), and typically groups will save their two-minute burst for a reopening on Nael. This should always be discussed with your group as a whole. Your goal at the end of Twintania is to have as much Battery as possible without overcapping your gauge, in addition to having enough Heat to enter a Wildfire window on demand when raid buffs go up in Nael. Regardless of whether or not you use a second Wildfire in Twintania's phase, you should still be using Barrel Stabilizer on cooldown.

Tactician uses here will not vary much. I am a fan of using Tactician in one of the open weave slots during our opener because it will cover the fireball as well as the follow-up tank buster if timed properly, but use this skill according to your group's needs. Avoid using Tactician during Hypercharge if you can. Missing a weave with two stacks of Gauss/Ricochet can overcap you easily.

From the point of Twintania dying to Nael becoming targetable, 24 seconds will have elapsed. This is enough time for a Drill cast, if you are capable of getting it off while Twintania is above 0.1%. It is safe to hold your group's two-minute burst for the three-minute buffs to catch up, if applicable. If your group opted for using two-minute buffs at the end of Twintania, Wildfire will come back around third Fireball. You only get one use of Wildfire in Nael, so holding here will not matter. If you do not use pots in phase one, you can opt for potting in Nael early on in prog to avoid possible enrages.

Machinist has the benefit of full uptime in this phase, so regardless of which mechanics you get and the order you get them, our rotation should stay intact. When Dragon Dive markers start to go out, take note of your gauge. If you are close to overcapping, getting out a final Hypercharge may be worthwhile before Nael jumps away. Depending on how low your group gets her health to, you will be able to get some last-minute GCDs to build Heat/Battery before Seventh Umbral Calamity.

Tactician can be used anywhere in the first half of the phase. You will want to make sure it is back up for Bahamut when your group decides they need it. Thermo stack at second fire is my preferred placement.

The point of Nael leaving to Bahamut becoming targetable is 17 seconds. Basically, a late Drill or Hot Shot is safe on Nael, as Drill will come back for your first or second GCD while Hot Shot can only be used once for the first damage phase, and it will not make a difference. The only time you should hold Hot Shot on Nael is if it will overcap your Battery, in which case holding would be more beneficial.

Our second pot window has two options. The first pot option is meant for groups who hold two-minute buffs in Twin, which should happen immediately after the transition. The second pot option would be preferred if you have opted to rush buff windows, meaning it will get used during Quickmarch.

The active phases and their lengths are listed as follows.

1. Seventh Umbral Calamity: 23 seconds, followed by 12 seconds of downtime.
2. Quickmarch: 30 seconds, followed by 18 seconds of downtime.
3. Blackfire: 33 seconds, followed by 17 seconds of downtime.
4. Fellruin: 35 seconds, followed by 19 seconds of downtime.
5. Heavensfall: 33 seconds, followed by 20 seconds of downtime.
6. Tenstrike: 37 seconds, followed by 54 seconds of downtime. Finishes Bahamut Prime and leads to adds.

The active portion of this phase extends to 4:55, which means we can safely use Wildfire a total of two times during this. The first one happens at the start of the phase as already outlined, with the second one happening during Fellruin. At this point, if you have been using Barrel Stabilizer on cooldown, it is almost certainly de-synced from your Wildfire windows. Take care with your Heat leaving Blackfire, as it is possible to enter Fellruin without the mandatory Heat to Wildfire here, which then delays Wildfire to Heavensfall and out of most (if not all) raid buffs.

A third Wildfire is possible in Tenstrike with early Wildfire usage in Bahamut, but most groups will opt to skip this two-minute buff cycle. However, it is safe to Wildfire here so long as it has been used on cooldown in prior windows. You will need to delay the pot in adds for this slightly, but this will not cost you a usage of pot if you are attempting to optimize. If you are progging, the third Wildfire should be skipped to ease alignment problems and allow you to focus on mechanics. It does not provide you any sort of benefit for the actual DPS required to clear.

Tactician in this phase is very free form. You will get two or three uses depending on the needs of your healers. Any trio works, and the uses do not necessarily need to be for Gigaflare. Examples of uses outside of Gigaflare are listed below.

1. Quickmarch - Used for Megaflare, Tank Tethers, and Earthshakers
2. Blackfire - Used for Thermo stack and Megaflare stack
3. Fellruin - Used for random dives, can also be timed properly to cover Gigaflare
4. Heavensfall - Used for knockback damage from the tower
5. Tenstrike - Used to cover Earthshaker damage

This is the only time during the entire encounter you will be placed in a two-target situation, and it changes our rotation priority slightly. Spread Shot on two targets is a gain over the single target combo, as is Flamethrower. Heat Blast is still preferred over Auto-Crossbow. The only thing stopping us from padding on AoE the entire time is the fact we will most likely be doing the Liquid Hell baits, as well as priority over the far Neurolink for Hatch. During Nael's quotes and at the end of the phase are good opportunities to get Spreadshot in.

There are two options for pot windows in this phase. If you have opted for using Wildfire during Tenstrike, your next Wildfire will occur about 30 seconds into this phase. To ensure our pot timings still line up for the two-minute burst on Golden Bahamut, we will need to pot slightly early compared to where Wildfire gets used. Pot usage for this timeline should be right before your second Drill in the phase. Wildfire will then get used after the third Drill in the phase to ensure we do not delay any of our Drill casts. Be mindful to not overcap Heat while attempting this.

The other option is just potting right as the phase starts, which means there was no Wildfire used at Tenstrike. This is the much safer option and should be what is done during prog. The reopener here looks like any standard opener you would normally do.

The end of the phase gets a bit tricky. When Twintania and Nael are both killed, we enter a transition that kills the entire party. Death results in losing any gauge we had tied to our character. To properly end this phase with as little resource waste as possible, here are the basic guidelines to follow:

1. When the final quote begins, start getting rid of any excess Heat you have. You will want to end your combo on a Clean Shot while being as close to 50 Heat as possible (not more than 60) while also having more than 50 Battery.
2. When able to, transition to Spread Shot, making sure to hit both targets, and continue to generate Heat until you have hit 50 gauge. Summon Rook and use Hypercharge for a final time.
3. Use Flamethrower until both targets are dead or the Flamethrower timer expires.
4. If the Flamethrower timer expires, continue on with Spread Shot and accept there will be unavoidable Heat waste. Kill times vary, and there is no way to ensure a perfect kill time with zero Heat waste.

Barrel Stabilizer in this phase should not be used past the second set of Liquid Hells, or you will risk not being able to open on Golden Bahamut.

Tactician should either be used with the first or second Megaflare. It will depend on where your other usages occurred and where you plan to use Tactician in the next phase. If properly timed, you can also cover the Death Sentence/Raven's Beak tank busters.

This phase is basically a nerves check. You will revive with the Phoenix buff, Phoenix's Blessing, which doubles all of your damage except the damage done by Limit Break. If you die, you will lose this buff. Not even taking parsing into consideration, it would be wise of you to not die during this portion of the fight. The earlier you die, the more effect it will have on your outgoing damage.

Since we enter the phase with zero gauge, and we only get a single pot in this phase, it is much better for us to wait until the two-minute mark to use it then. It is suggested you open with Drill and Hot Shot back-to-back, which will allow you to use 80 Battery at one minute and 100 Battery at two minutes to fully optimize both windows and get maximum potential from the pot window.

Tactician uses have two pathways here. Either you use it for Morn Afah one and Morn Afah four, or you use it on Morn Afah two and Morn Afah five. One and four may get better use since groups may not even see five.