One of the last trophies you will probably need to unlock the platinum is Beyond Rehabilitation, which requires you to beat Caroline and Justine. The twins is the hardest boss fight, it’s only available in New Game +. The option to fight the Velvet Room attendants becomes available when Mementos is unlocked, but you’ll need to prepare for this fight.
Stats: Each twin has 8,000 health and no weaknesses to exploit. Between the two, they can use attacks of every element. The fight will end in a loss if more than 50 turns is taken.
Preparation: Recommended level for the fight between 80 and 90. Since the Caroline and Justine can exploit every weakness, your party members should have their second awakening Personas from maxed confidant levels. Your character should use a Persona with no weaknesses as well, you could use one with firm stance and divine pillar to reduce damage by 75%. A Persona that repels Bless and Curse skills is nice for this fight.
Strats: Both have to be defeated in the same turn or one will revive the other to half health. If your entire party gets knocked down they will perform an all out attack to end the fight. If you don’t deal enough damage every turn, they will also knock down the whole party and use an all out attack. Casting buffs will buy you time as the twins will waste their turns casting spells to strip your buffs. Keep working them down and make sure to finish both off at the same time.
Expedite Ring – 1.5x exp accessory.
20x Balm of Life
5x Bead Chain
10x Soul Food
1x Omnipotent Orb – An accessory that nullifies all elements and status effects except Allmighty.
Double Book Mark – A key item that unlocks additional dialogue when talking to Lavenza nearing the end of the game.