Just fought the black sun Monolith boss Rahyeh the Black Sun. During an attack where he flies across the arena in a straight line down the middle he got stuck on the outer edge. I was able to hit him until he died, but all he did was shout voice lines at me and fly in place. I timed a rebuke during the exact hit time of his move but other than that I can’t think what could have interrupted him.
Also the black sun bosses in general have a move that I believe is called dark blast which produces a large timed AOE before it explodes for huge damage. Every time this move is used I have experienced an extreme drop in performance. I gave up trying to time rebuke for it at all as even when I just run out of it I still can still lock up and get hit for lethal damage.