SMT5V Sempiternal Vengeance Mod: Abdiel (Hard Mode)
Sempiternal Vengeance Mod: https://gamebanana.com/mods/566484
Abdiel's moveset has changed a lot from base game:
1) She now has War Dance and Fortification in her kit (this could actually be a bit annoying seeing as how her HP pool was doubled to 18k in this mod, which is a huge jump from the last major boss in this mod having 11.5k).
2) Her only physical attacks are now Myriad Slashes and Akashic Arts (don't expect Myriad to miss because she also has Dragon Eye in her kit).
3) Her Agi spells have changed to Narukami and Floral Gust (her Magatsuhi skill).
4) Light's Descent had its BP buffed from 220 to 300, which is quite huge and hits like a truck even with Light resistance, so I would advise against bringing anything with lower than resist.
This fight isn't really too bad mainly cause of the big exploitable AI quirk that came from base game: her innate Taunt effect on MC. You can still break the fight with Tetrakarn since she doesn't have Safeguard in her kit, but if not, you'd definitely want to grab an essence with Phys resistance for MC. I'd personally recommend Yoshitsune's since while he doesn't really resist any of her magic attacks, she isn't weak to any of them either (like Cu Chulainn, which is what I used here).