Stack the raid on one side of the boss, then when it appears, move through the boss to the other side, but watch out for the fire. At 75%, the boss phases into the shadow realm, so click the portal to follow him, but have a tank and healers stay behind for ...
it can be very hard to make the right calls on where to improve, what strategy needs to be changed, or who needs to step up their game. Analyzing logs from WCL helps you to identify problems in your raid, so you can solve them easier. Good raid leaders do this all the time...