Here's the basics from reading the subtitles and watching the video:
Composition: SAM BLM BLM BLU SCH GEO
Pro/Shell/Regen before entry
After entry, Entrust-Haste on the SAM, AOE Erratic Flutter, SAM roll (from sub /COR)
SAM tanks boss, SCH/BLM/BLM delete cactus with Immanence skillchain and Elemental Sealed Death (it gets an eva/meva spike during a skillchain so you need elemental seal).
SAM and BLU apply Ageha and Tearing Gust to boss, then BLU spams Sudden Lunge.
GEO does Ind-Frailty/BoG-Eclyptic Malaise, SCH gives BLMs Windstorm and uses Enlightenment to cast Blindna on the SAM (they'll be cutting it close with accuracy).
SAM skillchains: Jinpu > Ageha [Grav] > Shoha [Frag] > Kasha [Light] > Fudo [Light], then Rana > Shoha [Frag] > Kasha > [Light]
(Both BLMs are killing the sabotender with Death up until around Ageha, then Myrkr and cast Aeroja to burst the first Fragmentation, followed by regular Aero-line spells. SCH and GEO are bursting as well.)
As a side note the Japanese names for SCH abilities sure are exotic.
Also... it looks like the GEO is standing south of the boss so if you want to replicate this strategy and you're the GEO, stand on the east or west side of the boss for big Cardinal Chant gains :V