The September update that nerfed this was pretty severe.
He went from arguably the hardest of the bunch to a simple cakewalk. Nin's couldn't tank this thing unless you were pretty lucky/had extremely good support.
I remember fighting it a few times pre-nerf and it was a wreckingball with double-triple attacks hitting for upwards for 200+ per pop.
We popped it last week and two nin's dual tanked it without an issue at all. He rarely triple-attacked and when he did hit us, it was for ~100ish.
Lobais (taru) is probably the hardest of them all now, Astral Flow is still a killer even with the nerf.