Introduction

This guide contains suggestions on how to use your cooldowns effectively, and tips and tricks to play each phase as effectively as possible.

While most gearsets will work for UCOB, check the BiS sets posted on the site or in The Balance Discord server if you want to optimize your damage. If you have the Shadowbringers relic, we recommend a GCD speed of 2.45 or 2.40 to take advantage of the free Skill Speed provided.

While Dark Knight does the lowest damage of all of the tanks in UCoB, damage does not matter very much as the checks as very lax. Dark Knight does have an incredibly potent set of defensive cooldowns, especially since patch 7.1 where Dark Missionary is available for this ultimate. In particular, The Blackest Night (TBN) and Dark Mind overperform throughout this ultimate, and mitigating damage is incredibly comfortable.

Defensive Skill Usage

Ultimate progression is a team effort. Unlike Savage, incoming damage is so high and healer kits are small enough that GCD healing is not always avoidable. Because of this, how well you perform your job of mitigating for yourself, your co-tank, and your group will directly affect the performance of your healers. The Blackest Night (TBN) in particular is an incredibly strong tool, and smart usage will make a world of difference for your healers. Each phase will include notes on particularly heavy periods of damage on specific party members where TBN will likely be the most useful, and you can often ‘feel’ when an extra TBN would help, but it’s also up to your group’s healers to communicate where their resources are strained. It’s always a win for your party if you can save a player’s life, or make room for an extra damaging healer GCD.

One note for this encounter unlike fights from other expansions is that auto-attacks from bosses can crit, and deal a lot of your health. As a result, it’s especially important to be aware of and mitigate auto-attacks just like you think about tankbusters. TBN is extremely strong for mitigating boss auto-attacks throughout the fight.

Mitigation is rather flexible for this encounter, and further details will be provided in the section for each phase.

Offensive Skill Usage

Optimizing your damage on Dark Knight revolves heavily around shifting potency into raid buffs, and Ultimates are no different. For best results, coordinate with your group to know when burst windows are occurring. Generally speaking, you will want to pool resources for the start of each phase, with additional burst windows according to the length of the specific section and your party’s progress against enrage.

Note that it is impossible to provide a full map of each burst window because killtimes can vary wildly and your party will need to decide how to approach each phase. The following sections will provide guidelines on the more common options, but practicing and consulting with your group so that you’re all approaching phases the same way is important.

Potion Usage

While potion usage may depend on what your group wants to do, a recommended set of potions would be at the start of Phase Two (Nael), at the start of Phase Four (Adds), and at the second two-minute burst window for Phase Five (Golden Bahamut). Potting during Nael can allow a greater chance to skip dives, Adds is the most important phase to pot due to it being the phase where damage matters the most, and the last potion is essentially ‘free’ in Golden.

Use HQ Grade 3 Tinctures of Strength or better to cap strength for UCOB.

Phase One: Twintania

For your opener, pull with Unmend and do what’s essentially the standard opener, with a few minor adjustments and omissions. Obviously, abilities like Living Shadow and Salt and Darkness are omitted, but the rest should be as normal. Secondly, we recommend an early use of a defensive cooldown to cover the first Death Sentence if you are holding the boss for the first Death Sentence. Mitigating early is helpful because each Death Sentence requires a swap afterward, and early mitigation will catch the preceding autoattacks.

One note throughout this phase is that Twintania will also auto-attack while using Liquid Hell, leading to long strings of auto-attacks and damage, and it can be very beneficial to mitigate those where possible.

Most groups will see three Death Sentences in the phase, and it’s likely you’ll be taking either the first and third or the second, due to the swaps required after each. If you’re taking the boss first, Rampart after the second GCD should cover both the first Plummet and Death Sentence and can be used immediately to catch the third Death Sentence. It will then come back up for the second Bahamut Claws in Nael. Shadow Wall will last through the third Death Sentence if used just before the preceding fireball. Rampart can be used during the Generate castbar after the first baited Liquid Hells for the second Death Sentence, and Shadow Wall at the start of the second baited Liquid Hells.

If you’re taking the second Death Sentence, it happens at almost exactly one minute into the fight after a long string of auto-attacks, so it can be useful to start using your mitigation in the preceding seconds 20.

TBN should be used liberally to help with auto-attack and tankbuster damage. TBN is especially effective for Plummets because a tank who survives Death Sentence with any amount of HP will not need immediate attention. Do still use it for Death Sentences if required.

Most groups will hold 120-second and 60-second cooldowns at the end of the phase so that they have everything for the opener for Phase Two. You can send your burst for early progression, but it’s recommended to hold cooldowns for alignment. The tank that took the second Death Sentence (and therefore provoking the boss off the tank that took the third) will be the tank that’s starting with Nael and her double-tankbuster for the next phase, so be ready.

Phase Two: Nael deus Darnus

The phase will open with a Dalamud Dive on the tank who had aggro on the previous phase, followed by a Bahamut’s Claw multi-hit buster. This should be invulned. There are two more Bahamut’s Claws spaced throughout the phase before a Ravensbeak, which forces a swap, and then another Dalamud Dive into Bahamut’s Claw combo during divebombs. Generally, the tank who starts with Nael will hold her until the Ravensbeak, and afterwards, the tank that takes Nael usually will be the tank taking Bahamut first. This requires less tank swaps than swapping her regularly, but you can swap her more regularly for more mitigation options.

The second Bahamut’s Claw (the first that you don’t invuln), will happen about ten seconds after the first fire of the phase, and you can start mitigating with Rampart near the end of the first quote’s execution or when lightnings go off, and use TBN and Dark Mind when the attack comes out. The third Bahamut’s claw (the second that you don’t invuln) will come out not long after the third fireball (the second one taken by the full group). For this one, you can use Shadow Wall slightly before the third puddle appears, and use TBN as soon as you take the fire to cleanse your ice. After that Bahamut’s Claw, using TBN once off cooldown for auto-attacks will have it up again for Ravensbeak.

TBN can again be used very effectively in this phase, especially for auto-attacks and for quotes involving Thermionic Beam stacks. Dark Mind can be helpful as well. If you are targeted for Ravensbeak, the lingering vuln will cause you to take significant but nonlethal damage from Meteor Stream during divebombs.

After Nael dies, there’s a time to use tank LB for Seventh Umbral Era. Depending on killtimes and how focused your party was at building LB earlier in the fight, you may only have tank LB2 instead of tank LB3. It’s important to remember here that LB2 is longer than LB3, and you should use them at different times depending on what you have. If you have tank LB2, you should aim to use it before the first hit (Seventh Umbral Era), as it will cover all of the damage from the attack. If you have tank LB3, you should aim to use it immediately after the first hit, as that will most safely cover the most damage (the following Calamitous Flame and Calamitous Blaze).

Phase Three: Bahamut Prime

Dark Knight has an excellent suite of defensive cooldowns and can hold Bahamut for the majority of the phase with little issue, but you may opt to swap more frequently. Most groups will swap for every set following Quickmarch. You should ideally hold the boss for both triple Flare Breaths (the tankbuster set after Blackfire Trio and Heavensfall Trio) due to the strength of Dark Mind vs magical damage while other tanks have equivalents that work better for the Flattens.

Most parties will have 120-second cooldowns ready to go for the first uptime phase. If you used a strength potion for Twintania, you can use a potion there or after Quickmarch Trio and have it available again for the Phase Four opener. This is a purely personal optimization, as the DPS check is quite trivial and will frequently be met before Heavensfall Trio even begins.

The general plan for this phase is to take turns using heavy cooldowns from Blackfire onward. It is possible as well as and feasible, and generally recommended, for one tank to hold the boss for the first two set of tankbusters, with the next tank taking the post-Blackfire Trio as their first set. If you’re doing this, then the tank taking the boss second can provoke during the Blackfire Trio castbar. Cooldowns used post-Tenstrike will not be up for the first busters in the next phase, so plan around that. DRK and WAR invulns can also optionally be used without causing issues in Phase Five.

A recommended mitigation cooldown rotation for Bahamut is as follows:

• First uptime phase (Flare Breath -> Flatten): Ensure you survive the Flare Breath with Dark Mind + TBN and then Living Dead for Flatten.

• Post-Quickmarch Trio (Tempest Wing tether -> Flare Breath -> Flatten): Rampart + TBN as the individual Megaflare AoEs go out, and then TBN again for the Flatten. Rampart can cover all significant tank damage if timed well. You can TBN your cotank and forego personal mitigation if you are not holding the boss.

• Post-Blackfire Trio (3x Flare Breath): Shadow Wall during the Gigaflare cast, and then Dark Mind as the cast finishes. Apply TBN before or during the Flare Breaths. Rampart can be thrown on as well if you have it, though it isn’t necessary to plan around its availability.

• Post-Fellruin Trio (Tempest Wing tether -> Flare Breath -> Flatten -> Flare Breath): TBN should suffice for the Tempest Wing + Aetheric Profusion damage. You can take this set of busters if needed with Rampart and another TBN to cover the Flatten, but your co-tank will have more mitigation available and should ideally swap or Cover. If you did not take the Blackfire busters, you can full kitchen sink here. If you’re swapping the boss for each set of cooldowns, make sure the non-active tank provokes after the Flare Breath and brings the boss middle to prepare for Heavensfall Trio.

• Post-Heavensfall Trio (3x Flare Breath): Dark Mind + Shadow Wall + TBN, just like the first triple flares.

• Post-Tenstrike Trio (Flatten - > Flare Breath): This can be taken with available mitigation if you also held the boss after Heavensfall, but swapping is a much better option. Whichever tank took the boss after Fellruin should use their Shadow Wall equivalent plus applicable shorter-cooldown mitigations except Rampart. Living Dead is an option if you took Nael’s Dalamud Dive with it at the start of Phase Two.

Your first priority for Reprisal and Dark Missionary is the Gigaflare casts. With good coordination you can cover most of the tankbusters as well. Direct your melee to put Feint on Flattens, and your casters to put Addle on Gigaflares rather than Flare Breaths.

All abilities with cooldowns longer than 90 seconds should be held after Tenstrike Trio. 90-second cooldowns must be used immediately when Bahamut becomes targetable for the last uptime phase. Damage to Bahamut still counts for your parse after pushing him below 60% HP, but otherwise serves no practical purpose except resource generation.

Most groups will want to use Tank LB3 for Grand Octet if it is available. Stand clear of Twintania’s dive and cast LB as the towers appear and you will be able to move in time to dodge Twisters. If a tank gets targeted for the dive, they cannot be the one who uses LB. It’s also encouraged for everybody to use Arm’s Length/Surecast to prevent a wipe caused by a dive going awry.

You will gain about 3600 mana between Bahamut going untargetable for the last time and Nael/Twin becoming targetable. Try to enter Phase Four with full or nearly-full mana for the first two-minute burst.

Phase Four: Adds / Teraflare / Triple Threat

It’s recommended to use a potion in the opener here, as it will be back up for the second two-minute burst during Phase Five, and this is the phase where damage can matter most.

Throughout the phase, Stalwart Soul combos will generally be more efficient than single-targeting, however, due to the increased enmity on the Stalwart Soul combo, this can be dangerous and require additional coordination between your other tank. You should especially switch over to Souleater combos if one boss is nearing death while the other still needs some time to kill. Continue using Edge of Darkness instead of switching to Flood of Darkness, and use Bloodspiller instead of Quietus to spend your gauge.

Tank damage is extremely heavy in this phase. Use TBN liberally, and take special care to shield whichever tank is holding Twintania during each quote, especially if the quote involves a Thermionic Beam stack. Dark Mind is helpful for both quotes and tankbusters as well.

There are three sets of tankbusters during the phase. Each boss will open with the mini-buster from its associated solo phase (Plummet and Bahamut’s Claw), then perform a combo of its main + mini buster after the first cycle of mechanics, and finish with just their main busters after the second set of mechanics. You should TBN the first mini-buster, and it’s recommended that one tank reprisal as well. With the faster killtimes that are common now, it’s common to skip the last set of main tankbusters and the second Megaflare of this phase. Doing so will free up resources for Phase Five.

The second set of tankbusters happens just after the Megaflare following the first set of mechanics. You can Rampart as soon as you see the Megaflare cast to catch both the Megaflare and the tankbusters, and using Shadow Wall and Dark Mind as you see the tankbuster cast will catch the main and mini-busters. You should also TBN the main buster. Doing all of this will leave you light on cooldowns (Reprisal, Dark Mind, TBN) if you do see the third set of tankbusters, but GCD shields and attention from the healers will ensure you don’t die.

If damage is poor and you are seeing the third set of tankbusters, then each tank can take the first and third set with Rampart or other shorter cooldowns and the second, more dangerous set with Shadow Wall or equivalents. Rampart used for the third set of tankbusters in this phase will likely not be available for the first Akh Morn in the next phase, but this is not an issue for DRK.

With proper coordination between both tanks, Reprisal can be used on the first, second, and third busters, and both Megaflares. You can use Dark Missionary for the first Megaflare and have it up for the first Morn Afah in Phase Five.

Dump all of your resources before the end of the phase; the transition will kill you and you will start Phase 5 with full mana and zero blood.

Phase Five: Golden Bahamut

The first Akh Morn is not especially scary, and you can hold Rampart here to use for auto-attacks instead. TBN is, once again, extremely valuable in this phase. Golden Bahamut will attack five times in a row after each Exaflare cast and can randomly crit for over a third of a tank’s max HP while the healers are busy dodging, so it is quite helpful to apply any mitigation you can during these periods.

For the Akh Morns, most groups will look to invuln the second and third Akh Morns. This requires fewer resources, and the timing frees up more cooldowns to use for auto-attacks. Furthermore, the first Akh Morn hits for the lowest amount of damage of them all.

There can be situations where you’ll prefer to invuln the first and third Akh Morns, for example, if you see and need to heavily mitigate the third set of tankbusters in Adds, which will leave you short on cooldowns for the first Akh Morn. If you choose to do this, the timing for casting Shadow Wall to cover both the second and fourth Akh Morns is quite tight; any earlier than the third auto-attack after the Exaflare cast and it will fall off before the second Akh Morn finishes, and any later than the fourth auto-attack and it will not be off cooldown before the first hit of the fourth Akh Morn. Err on the side of being too early if you must do this, as the first Akh Morn hit deals twice the damage of the rest.

You will also be expected to use Reprisal for every second Morn Afah. One tank will be responsible for the first, third, and fifth cast, and the other for the second and fourth. Tanks will also be responsible for using their 90s raid mitigation (for us, that’s Dark Missionary) on the first, third, and fifth or second and fourth casts, respectively. The timing can be tight to get the third Morn Afah as well as the first with a 90s mitigation, so make sure you hit it a little early for the first, if you’re using Missionary for those Morn Afahs. Consistency is important here, as Morn Afah requires multiple stacked mitigations for the party to survive and missing more than one is likely to lead to deaths and potentially enrage. The third Morn Afah in particular tends to have the thinnest mitigation in most plans.

Since the DPS requirement is quite low, it’s recommended to use tank LB for safety for upcoming Akh Morns or Morn Afahs, especially if there’s any uncertainty or there’s, for example, a death. While it’s not required, it can single-handedly save a run, and is recommended for consistency of clearing. It’s important to remember that a death in this phase is much worse, damage wise, than a death in any other part of the fight, due to the Phoenix buff. A death will take a player from 200% damage to ~75%, due to the weakness debuff, and realistically, deaths will be the only thing that will cause you to hit enrage. Play safe, and don’t skimp on mitigations or tank LBs for safety.

Coordinate your burst windows with your group. Many groups will use all cooldowns at the start of the phase, and save their potion for the second two minute burst in the phase.

A final word: Don’t get discouraged if the number on your FFLogs page after clearing isn’t what you hoped. UCoB rankings in particular favor long, messy kills that spend as much time as possible on Phases Four and Five to take advantage of two-target cleave and the Phoenix Blessing buff. Excellent play can easily result in relatively unimpressive numbers, and often, playing for consistency of clears can run counter to getting a high parse.

Best of luck with your clear!