Joker - Yoshitsune - Divine Pillar
Hassou Tobiv | Endure
Charge | Regenerate 2
Diarahan | Regenerate 3
Arms Master | Repel Ice
Joker's role is to charge and then Hassou Tobi, that gives enough damage to see you through the damage requirement, he can have one turn per cycle where he does something else but anything more than that is game over.
I added Repel Ice after my fourth failure, because I kept getting frozen and missing a turn with zero action always meant I lost. Diarahan is there for emergencies but I never used it, another repel or an absorb would be better there.
Starting line up: Makoto, Yusuke, Haru
Makoto and Haru only get their weaknesses targeted in phase 3, while Yusuke is the most useless party member but can also reflect gun and physical damage and the aim in the first round is to not get hit with a critical. Makoto heals while Haru keeps Joker buffed with Heat Riser and dishes out one shot kill if one of Jokers attacks misses one twin or Mapsiodyne for supplementary damage. Yusuke keeps speed buffs up then does single or all damage when required (he only does chip though). Yusuke should survive the fire round due to his evade, or if he gets hit he will endure and then Futaba will save him.
The twins should have fully healed themselved by now and eventually they break out the nukes and psi attacks, in my experience Makoto and Haru are dead as soon as this happens and all of your buffs get removed, HOWEVER Futaba will swap them out for Ryuji and Morgana. Ann was never subbed, and that's a good thing because Ryuji immediately needs to put the Attack buff on and Morgana with the Speed debuff to the twins. Yusuke swaps out for Ann because its big damage time.
Ryuji charges and uses Agneyastra then buffs, Ann concentrates and uses Blazing Hell while Morgana heals. You have to get lucky with the twins staying around the same health, Caroline takes a lot of reflect damage so I found it was best to use a few single target attacks on Justine with Ann and Ryuji to keep them both level. You also have to get lucky with evades on turns where they target a weakness, you can only use one turn with Joker per cycle to get everyone back to life but the only real danger comes with the Elec / Wind turn where one of them always got hit. Provided Caroline doesn't reflect kill herself they go down way before the final phase begins and they get jacked up to hopeless levels.
Tough, frustrating fight. Much harder than P4's, but fairer than P3's.