For completionists, when does brute force stop working?

Im using guide cause I'm lame and I'm halfway through caelid. so far brute force with the blood fang has worked on all the bosses except that knight in west limgrave evargol. I know I ruined most of the game for me but I was intimidated at how many people call this or the genre itself very challenging.

Wondering when brute force stops working because it's kinda underwhelming my experience lol