How long it takes to bring down Nameless King

It's like 3 or 4 days that I'm trying to beat this mtrfckr. I'm not a hard player (play for an hour and a half daily, more or less, and not every day). I perfectly get the first phase, muscule memory goes pretty well. My problem is the second phase. I understood that I have to get the rhythm of dodging and attacking. Still, I'm curios about how long it takes to get it and finally beat him down (we all know this piece of cr*p kills with just two hits).

Edit: I finally beat him. Using bow was a fundamental part for reaching the win. Thanks guys