Yeah, I guess some bosses have so much initiative/agility that they take their turn multiple times before it's your party's turn.
The most recent one that grounded me down was the Chromatic Abbest, and besides just having an insanely large health pool, it would constantly take 3-4 turns before I got one.
Technically it's quite easy to dodge its attacks, but you have to do them so many times that it's just statistics that you're gonna ultimately fumble. I think I may have maxed out at 20-30 turns before I again lost one in my party; and then it was all over.
But maybe I'll try it again, now that I have Maelle with me (and I need to go to camp and see about that cool looking necro dude, from where you find Maelle, and see if he'll also join me?)
This is the one I'm referring to.
View: https://www.youtube.com/watch?v=C6ZjFMwZUW0
EDIT: holy hell, I only just now realized you can revive your party members? I don't think I ever access my items midfight. I wonder how rare those revive tints are.
Also, I assume when you die you reload your last save, and don't just revive, having lost your used items?