There's an attack this boss does where he charges up for a moment and unleashes an attack. A message appears saying "Baalride is getting ready for a massive attack. An assault will stop his attack preparation." While charging this attack his super armor bar disappears and a "counter" bar appears. I've tried hitting him with everything and nothing has been able to stop his attack, move the counter bar, or even do damage. In a video I saw a 3 person party also couldn't damage him or move the counter bar while he was charging.
Below is a link to a recording where I try to stop his attack with several methods.
