Easiest boss in the game may be a bit of an exaggeration, but he's pretty much right. Parrying Gwyn makes him ridiculously easy. If you have trouble with consistent timing, wait for him to do a combo attack. Block the first hit, and then parry the second. The timing will always be exactly the same, and you'll know the second attack is coming. It makes it much easier than trying to react to his first attack properly.