Why do people not understand A8?

[Aelinau]

I still don't know what to do when the AoE circles and Arrow drop at the same time in A8 last phase.
For some reason I always die.
It's super confusing. At this point I think it's because I'm going in front of him and getting hit with something, but I still can't be sure. Thankfully I'm the only one that dies.

At that point if you are the one with the arrow split dmg part run to the boss soon as the aoe circles disappear everyone should head to that spot knowing it( or at least this is what's done the times I've ran it) soon as the mech goes off you need to run behind the boss to not get hit by his next att. I hope that helps some lol