The write-up which accompanies the above JP video translated half-assedly by myself below. Credit to the creator:
https://leaguemili.com/blog-entry-3496.html
Corse
Trigger: Xarc[S]; Fei-Yin
Mob Behaviour
All Monsters
Slashing -12.5% / Piercing -50% / Blunt +25%
Magic DT -90% / AoE DT -95%
Petrification/Sleep Immune (Other debuffs work)
Bozzeto Pishogue (Main)
DRK / BLM
Summons 4 skeletons at 90% and 30% with message, "The boss has donned a magical mantle" (or similar)
Blood Wep @ 25% - Removes all debuffs + Dmg Boost + -DT Effect on itself
Spells used depends on party's distance to mob: targets < 10 yalms = Magic dmg. buff (harmless); > 10 yalms = AoE Charm/Doom (dead) = stay within 10 yalms
Bozzeto Warders
Skeletons with clubs; regain (WS a lot)
Appear with hate reshuffle = they will all go after diff. people upon popping
Use Dark Cloud move; dark dmg, slow, def down, m.eva down
Strategy
1. PLD takes main and back tanks (faces away from the monster while holding it)
2. DD dd from behind main and take down main to 90% to pop adds
3. When adds pop, PLD has 2 duties: 1) positioning adjustment, 2) regain hate.
Positioning - PLD must remain facing away from the Corse but move so the Corse faces all of the other members of the party
Hate Mgmt - use vallation, valiance, plufg to grab hate (spam these)
4. After adds are down or mid if you aren't fast enough, main will use Hecatomb Macabre (aoe charm 15s/doom 20s). Wait for charm to wear and immediately spam holy waters OR if mage in party, cursna (or both).
5. Resume dd on main, PLD back tank
6. @ 30% HP, new wave of adds pop; repeat process from #3 above. PLD can use, sentinel, rampart, pallisade.
7. When main is at low HP it may Blood Weapon. PLD to shield bash dispel asap.
8. Bring main to 0%
Buffs / Job Related
COR: Chaos/Sam/DD
PLD: Aegis/Oboro shield/heals/hate tools via RUN
BRD: honor/victory/mad/dirge and ballad + thunder carol for PLD/GEO
GEO: Indi-barrier/geo-fury/entrust-haste/heal/cursna/dd
PLD: holy circle
Doom removal items are a big help here like Nicander.