General Fight Tips
Manafication’s damage buff and 110 second cooldown is granted by a trait at Lv.74 meaning that in Lv.70 content it functions the same way it did in Stormblood: with no damage buff and a 120s cooldown. As a result of there being no damage buff it should be used slightly differently than in level 80 and 90 content.
While you should still aim to finish phases with as much Black and White mana as possible, in the scenario that your mana is at 50 | 50 or below, you can use Manafication during downtime during or between phases to get it on cooldown faster. This should be done whenever possible to avoid the possibility of losing a use of Manafication throughout the fight.
Potions in UCoB should be used during raid buff windows in order to maximize the gain received from them. Just as with level 90 content you should still aim to get two melee combos under a potion buff whenever you can.
As always, Embolden should be used to achieve the best possible gains for your group. While many groups will likely opt to use 120s raid buffs at the start of each phase, it may be worth suggesting to your group that you instead use your second set of 120s buffs at the end of Twintania. By doing this, you gain an 8th use of Embolden, versus having only seven uses if you were to hold for the start of Nael.
The reason for this is that you will only be using two sets of 120s raid buffs during Bahamut Prime, regardless of whether or not you hold Embolden at the end of Twintania. By using buffs on cooldown, you get three Emboldens during the first two phases as opposed to two.
As with other fights in the game, Vercure can be used during downtime between phases in order to prepare a Dualcast for when the boss becomes targetable again. In addition to this, in phases where the boss isn’t targetable and heavy raid damage is going out, Vercure can be used to assist your healers with healing wherever it may be needed. This is especially useful during the Trios in Bahamut Prime as the boss is often not targetable during these mechanics.
Phase One: Twintania
The standard level 90 opener can be used in this fight, minus the two finishers you learn at levels 80 and 90. Twisters will lock in and spawn as you are finishing Enchanted Redoublement and using your finisher, allowing you to easily move into the fireball stack. Additionally, as you still have an odd number of combo finishers at this level, this opener will not cause any misalignment.
If you are marked by a Hatch you should try to slidecast your way to the Hatch and minimize the potential damage loss from the Neurolink debuff.
If you are not able to get a Dualcast before you step into the Neurolink, you can cast a Jolt while in the Neurolink to prepare a Dualcast for when you step out of it. However, depending on how the boss is positioned relative to the Neurolink, you may not have the ability to resolve the Hatch before your next hardcast GCD. If you have both of your procs available while you are in a Neurolink, you can cast one of those in place of Jolt in order to generate more mana.
Be sure you wait for the debuff to fall off before you Dualcast, as it often takes a second for it to expire after stepping out. You can begin to slidecast with under 0.5 seconds left in the cast, generally, to help with making sure the Neurolink debuff drops off in time.
Liquid Hell Bait
When the physical ranged is marked by Hatch, a backup person will be asked to either bait Liquid Hells or intercept the Hatch on the Neurolink. While it is generally advisable to have a healer—or a SMN, if your group has one—do these tasks, some groups may ask their RDM to do it.
In the scenario that you are doing a backup bait, consider holding Swiftcast or Acceleration when you can for any possible Liquid Hell baits, as it is not possible to cast between each bait.
For the final pair of Hatches and Liquid Hells, a random person will be targeted by Liquid Hells. You can store enough mana for a melee combo here, which you can use to keep uptime on the boss while avoiding the Liquid Hells if you are targeted.
Most push timings will generally want to use 2nd set of 120s raid buff cooldowns before Twintania dies in order to gain a use before Bahamut Prime. You should discuss this opportunity with your group in order to decide the most optimal strategy for the group.
Addle in this phase will be used to mitigate the Fireball stacks from Twintania. While you should discuss with your healers which should be addled, common ones to addle are the second Fireball before the first Neurolink drop if it is not skipped, and the Fireball during random Liquid Hell baits after the second Neurolink drop. You should avoid Addling the first Fireball to generate extra Limit Break Gauge.
Phase Two: Nael Van Darnus
Entering this phase you should be near enough resources to do a double melee combo reopener. However, your reopener will vary depending on how much mana you ended the previous phase with.
Depending on your push timing in Twintania, you may have to cast some GCDs for mana before entering a melee combo. Despite this, you should still be able to get your first melee combo off without any problems. However, if the first quote ends with Iron Chariot instead of Thermionic Beam, you may have to use your second melee combo after moving out depending on your mana levels.
If you need to wait until after Iron Chariot for your second melee combo, you can use Corps-a-Corps to get back in right after the AoE goes out in order to start your melee combo and also stack in time for Firescorched.
There are many mechanics in this phase that snapshot early and can kill you and the party instantly if not handled correctly. As such you should always be ready and willing to drop a cast if you need to in order to avoid a mechanic. Your priority should always be to stay alive, as losing one or two GCDs is far less of a loss compared to dying. Common mechanics where you may need to drop casts depending on alignment are Iron Chariot, Wings of Salvation and Thunderstruck. Holding your Swiftcast and Acceleration for movement in this phase can help mitigate these losses from movement.
When Divebombs targets are being selected, you can preposition yourself between the boss and the first Divebomb marker. In the scenario that you are selected, you can slidecast into the marker while maintaining uptime. As markers come out, you can move around in a circular motion to the other Divebomb markers in the scenario that you are selected for one of those.
Something you can also consider doing is holding a Displacement charge towards the middle of the phase so that you can have it available in the scenario you are marked with a Divebomb. You can use Displacement to get to your Divebomb position faster which can often help you gain an extra GCD if you are not prepositioned and need to move a large distance.
Addle in this phase will be used to mitigate Thermionic Beam. The most common mitigated with Addle is the Thermionic Beam in the beginning of the second quote, while another option is the Thermionic Beam after Divebombs if the quote is for a stack instead of a spread.
Phase Three: Bahamut Prime
You do not have enough time to execute three melee combos in your reopener. If you enter this phase with capped resources you can use Manafication before Verholy/Verflare in your second melee combo to get it on cooldown without overcapping.
This phase consists of multiple damage phases when the boss is targetable between mechanics. Continue doing your rotation as normal during these phases, but beware of using heavy hitters such as Verflare/Verholy and Fleche as the boss is becoming untargetable as there is a high chance of it ghosting. You should also discuss with your party which of these short damage phases you will be using your buffs in for the highest possible damage output.
Fleche and Contre Sixte
Whenever the boss becomes targetable, you should immediately use Fleche in the first oGCD window available. By doing this, you allow yourself to get two casts of Fleche per damage window.
You will only be able to use one Contre Sixte per damage window, so aim to use this when raid buffs are available.
Addle in this phase will be used to mitigate the raid-wide damage from Gigaflare. After every Trio, Bahamut will cast a Gigaflare, and a total of two (per caster) can be Addled throughout the phase.
Your second Addle usage in this phase will depend on your first one. If you are using Addle on the Gigaflare after Blackfire Trio, you can also Addle either the Gigaflare after Heavensfall Trio or the Gigaflare after Tenstrike Trio. If you Addle the Gigaflare after Fellruin Trio, your second Addle must be on the Gigaflare after Tenstrike Trio.
Phase Four: Adds Phase
Try to come into this phase capped, or close to being capped, on black and white mana.
As you will likely be using a potion at the start of this phase, you should use at least two melee combos under your potion. As we only have one finisher at level 70, we can fit three full melee combos into a single potion, which may be possible here but can be tight due to Hatch. If you attempt to do a triple combo, you must start your first combo immediately when the bosses become targetable at the start of the phase.
As this phase has two bosses targetable, you should be using Impact whenever the bosses are stacked. There are many mechanics which will cause them to split, during which you should use your single target GCDs as usual.
While it is important to keep uptime on the bosses whenever possible, be wary of greeting GCD’s in this phase as it can greatly affect Golden Bahamut. Any weakness gained here will carry over to the next phase when you receive Phoenix’s Blessing, so don’t be afraid to drop a GCD when necessary.
Addle in this phase will be used on one of the Megaflare casts from Nael. It is generally advised to Addle the first Megaflare cast as Addling the second one may cause you to not have Addle back in time for the first Morn Afah in Golden Bahamut.
Phase Five: Golden Bahamut
Due to the party death during the Phoenix transition, you will be entering this phase with no black or white mana. As a result of this, you should use Vercure to prepare a Dualcast before Golden Bahamut is targetable. You can also use Manafication after being raised to execute a combo under buffs in your opener.
If you use a potion in the Adds phase, you will not be able to use a potion in your opener, but a later potion is better for Red Mage as you can perform more melee combos under your potion and buffs later in the phase during the final burn window.
The Phoenix’s Blessing buff given to you for this phase enables you to deal double damage—however, you will lose this buff if you die. Be cautious to not be killed in this phase, as a lost buff can be the cause of an enrage. As with other phases, do not hesitate to drop a cast if you are not certain you will be able to finish the cast without dying.
Swiftcast and Acceleration Usage
There will be many times in Golden Bahamut that you will need to quickly move in order to dodge an Exaflare. It is generally advisable to hold Swiftcast and Acceleration in this phase for times when you need to quickly move and can not finish a cast.
Toward the end of the phase, you should aim for at least a double melee combo under your potion and buffs. A triple melee combo in your potion may be possible, but will depend on how well your mana lines up leading into the buff window.
Addle in this phase will be used to mitigate the Morn Afah stacks. You should discuss with your party where you will be using Addle, as there are five total casts of Morn Afah.
Using 90s mitigations (Addle included) on the odd Morn Afahs will give you three total uses, so you should be using it on one, three, and five if you have one caster.
If you have two casters and it is your job to mitigate the second and the fourth Morn Afah, do consider the timing of where you use Addle for the second Morn Afah. You have to use it a few seconds before the cast for Morn Afah begins, or it will be late for the fourth one.