Don't know if it's supposed to be this way, but atm, the only way to survive focalors aoe is to warp in the gate while he does it.
Could you replace the gate with a npc like noitome ?
Because atm, evertytime you want to survive aoe, you need to reset the dmg of your party. As a raid, ir's not really well thought
Or is it just not made to be killable at 105 ?