I don't know his AI (beyond what it says in the summary window) and I haven't seen any videos, but here's what got me a Rank 1 clear in 7 turns, without Olive.

My team:

• Esther (DPS, LB field, Lightning debuff)
• Reberta (DPS, buffs, Aquatic killer, mirage for turn 2, imperil-remover)
• Sylvie (Passive physical provoker, lightning imbue/buff, elemental resist)
• Chow (Magic cover, morale gain robot)
• Kaito (Debuffs, chaining, general miracle worker)
• Chizuru (DPS, occasional buffs)

Notes on the fight:

• UPDATE: ACSekai pointed out that the ST attacks ignore provoke (apparently targeting highest DEF unit), which means you're free to use Chow's provoke skill and its 75% general mitigation. Note that you will still want high general mitigation (such as from Sylvie's NF Magnus or Esther's BS CD) on the rest of the team, primarily for the turn following the first burst.
  • Now that the mechanics page is up, it doesn't specify that it ignores provoke at all... so maybe Sylvie's passive provoke was winning over Chow's active provoke, because she was in an earlier slot? I'm not sure what's going on here anymore... :-/
• You want your first burst to cap, which isn't terribly difficult, but you want his DEF/SPR buff cleared, which is the tricky bit.
  • ATK/MAG breaks appear to renew it for 3 turns.
  • He also renewed it for me on Turn 2 for some reason I couldn't figure out.
  • BUT, he also self-reduces it if you don't trigger a counter-attack, such that you can burst on Turn 5.
• Turn 2 he does a bunch of AoE physical attacks you're going to want to mirage your way through. I used Reberta's CD for this.
• Turn 3 is a heavy magic turn. I use both Esther's BS CD and Chizuru's SPR Magnus to survive it.
• Turn 4 I use Chizuru's DEF Magnus just for the extra buffing.
• Turn 5 is your burst turn to 49%.
• Turn 6 is set-up for the burst turn to 0%. This is another heavy-hitting turn all around so Sylvie uses her NF Magnus to aid survival.
• Turn 7, Kaito clears the boss' buffs before doing the kill.
• As usual, Chow is MVP for morale gain. The trick is that you want him at 95% Water and Earth resistance, so he's still taking damage from the elemental attacks to trigger his counter.
  • If you're using Sylvie's elemental resist abilities (80% Water, 200% Earth) you want his resists from equipment to be at 15% Water and -105% Earth. (I gave him a combination of Siren esper, Kryla's veil, Magic Sanctuary and Booster Cactuar to achieve this, but you can use any sufficient combination.)
  • I had him equipped with two Blizzard Orbs and Looming Wrath for counters.
  • Rest of the build was to maximize SPR and HP, as he still takes a ton of damage.
  • Note: his strong general mitigation is attached to his Provoke skill, which you don't want to use, so he relies on external mitigation from Esther and Sylvie. (Maybe there's a way around this by making Sylvie active provoke as well...) Turns out the provoke goes to whomever is in the earlier slot, so if Sylvie is passive provoking in an earlier slot you can safely use his provoke.
• Kaito is my other not-so-secret weapon:
  • Turn 1 I LB for 90% ATK/MAG breaks, and then Turn 2 I use his Magnus to extend the duration of those debuffs to 6 turns, so I basically don't need to worry about ATK/MAG breaks for the rest of the battle.
  • Obviously you need to avoid his fullbreak abilities, but his 150% morale abilities do 90% DEF and SPR breaks without breaking ATK or MAG, so once you've got sufficient morale you're golden.
  • I saved his other Magnus for my second burst. Use it on the kill turn, or else you risk that he will re-up his DEF/SPR buffs!
• Sylvie takes a wallop and is built for passive provoke (Dancer's Diadem) and DEF HP. Evasion doesn't work.
• Everyone else is built for their best DPS with Aquatic Avian killers.
• At least one of my clears, I used Kaito's Magnus early and was stuck with the DEF/SPR buffs in the second phase, but was still able to clear it with two consecutive burst turns. In this in case, I used Sylvie's Magnus to insta-fill Esther's LB, the Hyoh card CD on Chizuru to chain (who was forced back to normal form by then), and Kaito's LB. It's not hard to burst him down to 0% in two turns if you can survive through it.

Here's my rough blow-by-blow. In general, units should do their morale-generating moves or lightweight DPS attacks when not otherwise specified, both to generate morale and help break through the mirages that the boss puts up.

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