Finally beat the game. Lord Gwyn wasn't as hard as some of the bosses, the boss in the painted world was probably the most difficult for me, simply because she's invisible. All and all though it was a fun fight, I just tanked it with full havel armor, ring of steel protection, giant great ax, and the black knight great shield. His hits did nothing when i blocked, and didn't take up too much stamina either. The only issue was how fast he attacks, but with patience and good timing I killed him.