Ifrit Hard Mode

Phase 1 - Ifrit's Abilities: Incinerate - (Instant) A frontal breath which deals ~1500-1900 damage.
Vulcan Burst - (Instant) A blast around Ifrit which deals ~500-600 damage to all nearby targets.
Eruption - Cracks appear below a random player, exploding a few seconds later for ~2300-2800 damage.
Crimson Cyclone - Ifrit charges forward, dealing ~2600 damage to all targets in front of him.

This phase is nearly identical to Phase 1 of the Ifrit story encounter. The tank should back up to the wall so Vulcan Burst does not move them, allowing the ranged jobs to stand at max range without getting hit by Vulcan Burst themselves. When Eruption is cast, the Paladin should interrupt it every time. If you do not have a Paladin, set up a stun rotation between the Warrior off-tank and a Dragoon.

The only new ability in this phase is Crimson Cyclone. Ifrit will vanish and reappear on a random side of the room. He will briefly glow purple before blasting forward, damaging anyone in front of him. Just move out from in front of him and nobody should take damage. Try not to stand too close to the tank after the blast, as Ifrit will land on them and start using Incinerate fairly quickly.

Once Ifrit reaches 75% HP, he will shift into phase 2.

Phase 2 - Ifrit's Abilities: Incinerate - (Instant) A frontal breath which deals ~1500-1900 damage.
Vulcan Burst - (Instant) A blast around Ifrit which deals ~500-600 damage to all nearby targets.
Eruption - Cracks appear below a random player, exploding a few seconds later for ~2300-2800 damage.
Crimson Cyclone - Ifrit charges forward, dealing ~2600 damage to all targets in front of him.
Sear - (Instant) Deals ~200 damage to all targets near Ifrit.
Radiant Plume - A fiery circle is placed on the ground which explodes a few seconds later, dealing ~2400 damage.
Hellfire - Ifrit unleashes an Inferno, dealing damage to all players based on if the Infernal Nails were killed.

This phase will add the abilities Sear and Radiant Plume, as well as modify a few others. Radiant Plume will function just as it did in the low-level story, alternating between placing ground effects in the center of the room and placing them along the edge. You should avoid stunning Radiant Plume, as it is predictable and fairly easy to dodge. In addition to Plume, Ifrit's eruption will also change slightly. Instead of doing a single crack under each person, it will do a series of three cracks, one every second or so. While most of these should be stunned, some occasionally sneak past the interrupts, so if you see the second crack appear, start running. Finally, when Ifrit uses Crimson Cyclone, he will create a duplicate of himself. Both of these will use Crimson Cyclone a few seconds apart. If possible, I try to get fairly close to one side of them to ensure I will not be hit by the frontal. With careful positioning, you can also be between them.

Once Ifrit reaches 50%, he will spawn four Infernal Nails near the middle of the room. If you have a Black Mage or Summoner, use a level 3 Limit Break so that it will AoE all four nails. If you are lacking a Meteor limit break, a Monk or Dragoon should limit break the furthest nail from Ifrit to avoid being knocked back and interrupted. As the nails come down, the healers should also shield/stoneskin the designated melee to help prevent Vulcan Burst interrupting the limit break. All of the DPS should focus the next two nails down together, which should bring the limit break back up to level 2. Unleash it on the final nail and, if DPS was strong enough, you should have managed to kill all of the nails.

Once all four nails go down, Ifrit will leap into the air. Everyone should move close to the center of the room while Scholars pre-cast Succor and White Mages pre-cast Medica II. Scholars can also place Sacred Soil for the group to stack in, further reducing damage. As long as none of the nails survived and nobody is weakened, all the players should survive Hellfire. This also signals the start of the final phase.

Phase 3 - Ifrit's Abilities:
Incinerate - (Instant) A frontal breath which deals ~1500-1900 damage.
Vulcan Burst - (Instant) A blast around Ifrit which deals ~500-600 damage to all nearby targets.
Eruption - Cracks appear below a random player, exploding a few seconds later for ~2300-2800 damage.
Crimson Cyclone - Ifrit charges forward, dealing ~2600 damage to all targets in front of him.
Sear - (Instant) Deals ~200 damage to all targets near Ifrit.
Radiant Plume - A fiery circle is placed on the ground which explodes a few seconds later, dealing ~2400 damage.

This phase will feel chaotic the first time you reach it. However, it follows an exact pattern that, once memorized, makes it much easier. After Ifrit vanishes, he will create three copies of himself and use Crimson Cyclone. Once he reappears, he will use Radiant Plume along the edges of the room, followed shortly by a Radiant Plume in the middle of the room. Not long after these, Eruption is cast. This is the most important Eruption to interrupt. If it goes off, it will likely cause people to be out of place for the next ability, Radiant Plume. Unlike the previous Plumes, this will use a new pattern, filling up most of the room except for a small section near the boss. As soon as the Eruption is interrupted, everyone should stack into melee to prepare to dodge this plume. Once it goes off, Ifrit will retaliate with another Eruption before vanishing and starting the cycle over with Crimson Cyclone.

In short, the pattern is Crimson Cyclone > Outside Plume > Inside Plume > Eruption (Interrupt) > Stack in melee immediately to avoid the Full Room Plume > Eruption (Interrupt).

OVER VIEW

All Phases

Tank with your back to a wall so Vulcan Burst doesn't push you around.

Only the tank should be in front of Ifrit at all times.

The Paladin should be the off-tank on interrupt duty. Interrupt every Eruption throughout the fight and nothing else unless it's an emergency. If there is no Paladin, the Warrior off-tank and a dragoon should do a stun rotation.

When Ifrit vanishes and appears near an edge, move out from in front of him.

Phase 2

When Ifrit vanishes, he'll now create a copy of himself. Both will use Crimson Cyclone, so do not be in front of either one.

It is vital to interrupt most of the Eruptions to charge the limit break meter. It needs to be at three bars when Ifrit reaches 50% HP.

Never use the limit break before the Infernal Nails spawn.

If you have a Meteor Limit Break, use it so all four Infernal Nails are nearly killed. If you do not, immediately use a melee LB on the furthest nail, focus down two more nails, and use another LB on the final nail.

After the nails die, pre-cast Medica II and Succor to heal through Hellfire.

Phase 3

Ifrit will now create two copies of himself during Crimson Cyclone. There will be a slight purple glow around the one about to charge.

A strict pattern is followed. Crimson Cyclone > Outside Plume > Inside Plume > Eruption (Interrupt) > Stack in melee immediately to avoid the Full Room Plume > Eruption (Interrupt).