It's one thing for a struggle with Erebonia to get mentioned a lot late in the game, but it's another entirely for the ending to just drop the "Crossbell falls to Erebonia" thing just like that. That must have been really bittersweet for people that played this game without knowing what was to come. I think I used the cast arts/attack method which worked well, till the last 20% which is when you use all of your burst orbs, which works because you're delaying them from using their s-craft. Overall, this is supposed to be the hardest fight in the game, but with this strategy, it should be a cakewalk. If you still can't do this task, then cast stealth on your party members to avoid getting hit. When the boss has around 20% HP left, it will absorb one of the mobs to greatly power itself, during this phase it will use its ultimate attack which will cause Vanish on the entire party, which is an instant game over, to avoid this, you should use Burst (Use a burst orb if you're unable to fill the Burst gauge) to kill the boss before that happens.
#AO NO KISEKI PC CRASHES AT ARIOS FIGHT FREE#
It will lock the computer into this pattern where the last boss will try to dispel one, while the other members gets away with landing free hits on the boss Do not try to cast it all at the same time, if you did it correctly, the boss will try to impede one of the arts users spell casting, while the other one attacks. Then have your three characters trade turns on casting arts.
Then have your evasion tank (Preferably Rixia for Dragon Claw) to pull all the mobs to her corner. What you should do is move everyone to each corner of the map. The last boss might appear to be super hard on nightmare mode, but it can also be easily cheesed. That's the strategy i used (i assume you've already seen this walkthrough)