This boss took me about 15 hours in total. Being able to withstand only one of his direct single-sword attacks was a bit painful...
This is the only boss in the entire game that made me use a shield, because of one double slash attack, which is not dodgeable unless you have a good position (and it's not really the same case as Malenia with her Waterfowl Dance, because it was her ultimate attack, not a part of the moveset that she can use randomly). On 2nd phase, getting hit by the second attack makes you take hit from the light followup as well, which in my case resulted in guaranteed death. I got tired of this, so I took a shield. However, I didn't abuse shield-poking strategy and learned...