ARMORED CORE 6 FIRES OF RUBICON IBIS Boss Fight Cheese strategy IBIS Series CEL 240

The trick is to continuously strafe and bait the boss into lunging behind you which gives you the opening to hit him on the face with double stun needle, and follow up with the javelin. Keep your fcs lock on at medium range and take the shot even if he lands behind you and is not on screen- if you time it right you will get the hit on the boss. Both phases play the same, only in the second phase make sure to fly up when that phoenix attack happens. Best of luck, Raven!
This is imo one of the worst boss fights Fromsoft has done in recent times. Glad I could beat it before they inevitably nerf the difficulty.