I know this crash battle is very tough dps fight because boss had 5.2m HP.
If you have same setup like me this will help
Tips :
* Alway use Aerith buff like me did at early half fight because it will disapear right time after heavy hit from boss.
* Try to control DPS - Sub DPS don't hit long animation skill while boss nearly cast skill because the new mechanical to fillup Summon/LB sck.Even u may hit the boss but it won't fillup your gauge then that will slowdown you to get summon right before bomb burst.
Good luck and tks for watching :)