For me it’s Blood-Starved beast and Rom. I find them easy bosses and sometimes manage to beat them first try, but occasionaly I find myself struggling in subsequent playthroughs (depending on my build). I’m currently replaying and died to Rom a lot 😅BSB has an annoying attack that is pretty much an insta-kill cause of the poison and it’s really a vigor check
Blood starved beast is definitely a thorn in my side more often then not.
BSB is super annoying on any playthrough. On my BL4 run, I just couldn’t kill them even if my life depended on it. Took way too many tries