After entering the room, pass him from his left with a roll and get up the stairs. Use that to kill the dogs and get down to make some distance and heal yourself if necessary. After that I fought him like normaly: I blocked all horizontal attacks and dodged the vertical ones. If you learn the timing, you can dodge towards him when he uses the manchete slam, creating a window to attack him one or two times. I was using the pyro clothes with grass crest shield +3 amd longsword +5. My rings were the wolf and the blue tear ones.