Rematch with LOT2's Final Boss (VOLUME WARNING)
This half a year later rematch ended up being complete overkill. I went with my party from my Hard Mode run with some additions but ended up not even needing certain characters (like Aya or Hina). I'd say the MVP here was Yuyuko. Flandre did big numbers but Yuyuko straight up made one of the other party members, Hina, obsolete (I usually have Hina use Pain Flow to take care of the phase with the goons, but as you can see, Yuyuko destroyed them, even with them fully buffed). The party set up is:
Guardian Mokou (used Guardian for its hidden ability to draw aggro), Strategist Komachi (used Strategist for its passive), Enchanter Reimu and Healer Eiki for their damage reduction passives (Reimu drops SPI damage by 30%, Eiki drops all elemental damage including SPI) with Gambler Flandre (damage boost) and Sorcerer Yuyuko (her strongest spell for this fight, her DRK Row Attack, can be boosted with the Row Attack passive on Sorcerer). BTW, the reason you want to go with the Row Attack DRK spell is because it only factors in 50% of Murakumo's MND. I also had a Hexer Momiji I was testing (the idea was I'd sneak her in for whenever Murakumo used World Shaking Military Rule. Her Perceiving Eyes would let her tank Murakumo even with buffs, and Hexer's spells would allow Momiji to drop Murakumo's stats with debuffs. It didn't work as well as I'd hoped tbh).
Everyone else had library upgrades up to cost 500. HP, DEF and SPI and PHYS resistance were up, then I went with ATK or MAG depending on the character (e.g. ATK for Kogasa, MAG for Hina). Between all that SPI resistance, Strategist Komachi's passives and Reimu and Eiki's damage reduction, equip slots could be dedicated to damage boosting or ailment protection items (i.e. PAR and DTH). Music is Present World Overhaul from Len'En 3. The music was live (i.e. not added in post) which is why it's louder than it should be.