After completing the game 100% solo, the only boss I that caused me some proper frustration was
. That second phase, PhhhhEEEW..
Though, I seem to have missed a lot of content, if this thread is anything to go by.
Which I can't understand, cause I've been really thorough, and have went through all the areas several times.
All in all, the game wasn't as difficult as I had hoped. (Sorry to the guys who's having a hard time.)

Could be cause I went with axe, and then great sword for the rest of my play through.
One level costs me 70k souls now. With STR at 50 and my great sword maxed out, there isn't really any way I can upgrade my damage output anymore, which kinda sucks.