You can read on Wowhead forums, on reddit forums, and even on these bug forums all about it.
His Ocular Beam is not supposed to aim bot you. You are supposed to be able to avoid it. Not to mention, there are many occasions where you are not near Aerial Stikes (and when I mean not near I mean not even on the platform, I heroic leap out of the whole area with my Warrior) and still you get hit by it.
It’s been well known since launch this boss needs fix and tuning, especially when you hit the innevitable RNG of twisting corridors and get him as a last boss with 47% damage increase. NOTHING will save you from the ticks of his beam because it auto-focuses on you.
Like I said… I have defeated him before. This isn’t a “git gud” issue. He has been messed up for more than a year.