I always find it funny how some of us struggle against certain bosses, while others have little trouble at all.
Demon's Souls and Dark Souls 2 were the last Souls game I played in the series (late bloomer). Leading up to them, I kept hearing how difficult False King Allant, Flamelurker, and Maneater for DS were. For DS2, it was Flamelurker and Si ALonne. Even on NG3 or 4, they were all pretty easy for me. Maybe I just built them up too much in my head.
The Nameless King for ex, I had to resort to cheesing him, constantly running away using arrows. The camera always fucked me early when he's on his drake, but even one on one I just couldn't get his timing down. Outside the shitty camera for the first phase, he wasn't unfair, I just took the easy out.
The Gank squad trio boss in DS2 almost made me smash my tv. Same as the Blue Smelter Demon. Even getting to that fucker was tough. I died so much there were barely any enemies left by the time I beat him.
I had other difficult bosses, like the Burnt Ivory King (more a hit box thing), and especially Midir in DS3, but it was more his crazy health pool.
Kos is just on another level, my toughest, Manus a close second The last time I played either, It took me about 50 tries. They are both fair tough fights though, unlike consort Radahn, who I really hated. It prob didn't help that he was the final boss and not Godwin or Marika. I disliked everything about that encounter/ending lore wise, so I was extra crusty lol.
I don't know how guys like you
@Ashen One do consistent no hits, likely at far lower levels too, as I would grind souls from time to time.