I never got past Artorias. That fight and the one against the big lion upset me. They weren't designed like the rest of the boss fights in the game. All of the bosses leading up to it could be handled in a very methodical way. Stand back, play defensive, keep your shield up, observe the enemy, learn its pattern, go in for pokes when it's exposed. The boss fights in the DLC were like, let's throw a bunch of SSJ4 Goku motherfuckers at you ninja flipping and spamming attacks so fast you can't think.
I eventually got good enough at being the lion, but then the forest area after that pissed me off really badly as well. I'd try REAL hard to methodically and thoroughly explore the area and get all of the loot out of it like I had been for the entire rest of the game, but the perfectly spaced out enemies that would always come in groups of 3 with a gigantic dude that practically one shot me, I eventually got fed up and just sprinted thru the whole place.
Then I got to Artorias and it was yet another fight where the guy flew around in the air and never stopped moving and attacked repeatedly and relentlessly, and it was just tedious. Far more tedious than anything in the vanilla game save for maybe the Bed of Chaos.
I just got tired of it and gave up. Still haven't gone back to that DLC area in any character since the first one. I might some day, but those first two fights and that forest area have left such a bad taste in my mouth with how cheap they felt I don't feel the need to.