Master Trial - Black And White

I use:
RNG/WAR RNG/WAR COR/DNC GEO/WHM WHM/SCH PLD/WAR

Note that the JP video uses:
RNG/NIN RNG/NIN COR/mage GEO/RDM SCH/RDM PLD/WAR

The primary reason I took the setup I did was breathing room. Their win left extremely little room for error, and I can't imagine how many runs it took to achieve those results. Losing Embrava hurts at the start, but cureskin gives you much more reliable results throughout the fight. COR needs DNC sub to land shots effectively, gaining an additional 34 r.acc from a kustawi offhand and accuracy bonus trait. RNG/WAR is probably not necessary, as ratio is capped on everything except alexander when buffs were up and frailty has either blaze of glory or ecliptic attrition. Would come down to fencer vs what /SAM offers. If you want the security, you can sub NIN. It really won't save you when ***starts going terribly wrong, though. Note that my setup doesn't have flurry, which means you need capped snapshot through gear. This may or may not be reasonable for you, so if your COR isn't highly decked or you don't want to mess with snapshot give the JP setup a try. Keep in mind that they win at 58.5/60 minutes, and if nothing goes wrong my setup clears in under 50. My win had several large mistakes and I still had 3 minutes left as it died.

Geo uses Indi-Fury, Geo-Frailty. Entrust Indi-Haste on PLD immediately upon zoning in and whenever entrust is up and it is down.

COR uses crooked hunters and samurai roll(1330 accuracy prebuffs alongside sublime+1 and crooked hunters had me at cap or close on everything in zone). I aimed for a 2, or a 7+ for samurai roll, allowing me to build my annihilator 3hit and fomalhaut 4hit(both rng and cor) around having an extra 36 stp. This means a small chance of busting going 6>12, but with fold it's not a problem. It's better than trying to roll aggressively. Obviously a better roll is a bit more carryover tp when using fomalhaut.

WHM should start off with shellra, protectra, accession stoneskin and maintain boost-agi for the RNGs.

Start by aggroing everything on the PLD and lining it up against the wall to your left when facing arena. You will need aegis fulltime. Mobs will path to their left, so backing up with a wall to your right helps to get them cleanly lined up. It should look something like this:
Once positioning is correct, you can start damaging the fomor. WHM should do nothing besides cure and only reapply boost-agi when thoroughly confident. GEO should handle at least erase/haste, I like to do silena on it as well for valfodr. PLD needs holy waters for valfodr and panacea for massacre elegy. Note that panacea doesn't actually remove elegy, but it will remove the cluster**** of other debuffs. Thus, someone should be ready to cast erase as PLD begins using panacea to guarantee it's off. Ofnir is extremely dangerous, PLD should have their finger on panacea as soon as they see it readying. Two weaponskills during the defense down can kill you, even if your PLD is essentially maxed(in my case: 3200 hp, 67% pdt, -10% enemy crit). If the PLD is stunned during ofnir, WHM needs to make a judgment call and immediately sacrifice or alternate cures 4-6 to keep cureskin up until the PLD has a chance to panacea.

Bolster as soon as pull is clear and you're ready to start DDing. Random deal, if it hits entrust wait until you can recast entrust haste before wild carding. If wild card hits bolster, do a second when it wears off. It does relatively little due to capped or near capped ratio, but since the BC lasts an hour there's no point holding onto it(you'll want it back up ~50 min in for odin or alex). Continue to entrust haste as possible and random deal when it's down, it will give the PLD much more breathing room. Dia2 and double light shot everything. My recommended kill order is:

Helmwige -> Ortlinde -> Grimgerde -> Schwertleite -> Remaining 4 are identical as far as I can tell -> Waltraute last

Mob-specific notes:

Helmwige - The most dangerous of the fomor, needs to go first. Uses Chainspell, Elemental Sforzo.
Spells: Stonera 3, Watera 3, Aera 3, Fira 3, Blizzara 3, Thundara 3, Kaustra
WS: Vorpal Blade, Chant Du Cygne, Requiescat, Sanguine Blade

Ortlinde - Recommended to kill second. Casts many aoe buffs that will effect all 9 fomor. Uses Chainspell and Elemental Sforzo.
Spells: Protectra 5, Shellra 5, Phalanx, Hastega, Embrava
WS: Requiescat, Sanguine Blade, Vorpal Blade, Chant Du Cygne

Grimgerde - Horde Lullaby II will remove PLD from hate list of all fomor, whether or not Grimgerde is your current target. Uses benediction at low HP, resulting in a much longer fight than the prior 2. Once Grimgerde is dead, the scariest part of the fight is over, and hate will be much more predictable. I've still seen instances of hate being dumped, so something else may trigger it as well. Keep an eye out.
Spells: Horde Lullaby II, Massacre Elegy, Light Threnody II, Knight's Minne IV, Knight's Minne V
WS: Entropy, Shadow of Death, Quietus, Infernal Scythe

(NOTE: Due to hate reset, it may be advisable to kill first. However, in my experience, the PLD runs a high chance of dying to Helmwige, especially after Ortlinde starts buffing. Usually, you can kill Helmwige and Ortlinde fast enough to avoid any catastrophic issues from hate loss.)

Schwertleite - Uses Chainspell and Elemental Sforzo.
Spells: Silencega, Blindga, Graviga, Paralyga, Slowga
WS: Requiescat, Sanguine Blade, Vorpal Blade, Chant du Cygne

Rossweisse/Siegrune/Gerhilde/Brunhilde : Use mighty strikes and invincible multiple times. No spells, all use the same WS. There's not much else to note on these, just keep your eyes out for ofnir and don't lose focus.
WS: Stardiver, Camlann's Torment, Raiden Thrust, Sonic Thrust

Waltraute - With everything else dead, not much to worry about. Will use benediction. Doesn't seem to have the same hate reset properties as Grimgerde, but still subject to the random hate dumps.
Spells: Magic Finale, Valor Minuet V, Valor Minuet IV, Advancing March, Vicotry March
WS: Quietus, Entropy, Infernal Scythe, Shadow of Death

These hate dumps are absolutely a mechanic, not just enmity issues. In many cases, the mob will run over and one shot a RNG(despite COR doing comparable damage without coronach's reduced enmity) and then sometimes even go idle. I don't know what triggers them aside from horde lullaby, but it absolutely does. Poison potions are advisable until grimgerde is dead so you can quickly provoke or flash to get back on list. Self target JAs, even invincible, will not help, indicating that PLD's hate is completely dumped.

If you can get through the fomor with at least 25 minutes left, you're looking good. RNGs should switch from annihilator to fomalhaut for Alex, you can swing either a 3hit or a 4hit. Note that if you use a 4hit or exceptionally geared 3hit, you'll be able to drop hunters roll for chaos. COR is pretty much limited to 4hit to have sufficient accuracy.

Alexander doesn't do much. If RNGs are at 20' they will never be damaged. Hate dumps don't seem to ever happen on him, and I've never had a RNG pull hate during the fight. He has a lot of HP, and it should be expected that you could take over 10 minutes killing him. Will use perfect defense and the light damage aoe below 50% HP, never seen either of them used twice. Light damage move doesn't hit 20' away and does very little to aegis PLD(<1000). This is a good time for WHM and GEO to recover MP. I recommend RNGs hold good JA at low HP, so they can be used on Odin. Make sure when alex dies everyone except PLD is over 20' from odin and all have reraise up(I'm assuming you'll read whole strategy before trying, but explained under odin).

Odin has the usual moves:
Ofnir - Defense Down, damage
Gagnrath - Damage, Terror
Geirrothr - 7500 physical damage divided evenly between targets within 20'. Used frequently below 75%, keeping luopan resummoned quickly is important.
Valfodr - Silence, Curse
Yggr - Allows odin to intimidate
Sanngetall - 20' full dispel, used only once between 50% and 30% in every fight I've done.

He also has two new moves:
Shin Zantetsuken - 20' Death. Anyone who currently has reraise active will lose it, and take about 1000 magic damage instead of dying. Everyone should bring multiple sources of reraise and keep them active. This will be used as soon as alex dies, and again whenever he feels like it as a regular tp move. Seems to be less common than the others, but seen as many as 5 in a fight. DD should be prepared to bazaar extra reraisers for PLD if needed.

Zantetsuken Jin - Cone Death, blocked by utsusemi. Can be used multiple times, but seems to be weighted quite low.

Furthermore, he has additional effect:chainbound on melee hits. A skillchained geirrothr can do over 3000 damage to a burtgang PLD, reinforcing the need to have a second target.

I never saw anything to indicate a hate reset associated with any moves, but hate is still shaky. I no longer shoot on the corsair, and I save wild card so that I can start with 6 minutes of decoy shot on RNG. Even if you don't have any of the strange hate issues, Zantetsuken Jin will cause problems. Shadowbind is very helpful for allowing PLD to unweaken(if you have time to do so), but if you are strapped for time and attempting to tank weakened on PLD, the COR should be in range at all times to dilute Geirrothr in the event luopan is dead at the time it goes off. I kept 2 reraise earrings on COR so it could freely reraise during that time. Yggr can make resummoning difficult with the intimidation.