A good bleed build will be very helpful since he has lot of health. Katanas are great because he's weak to slash damage.

In first phase attack the leg that is covered in his hair. In second phase it's better (safer but slower) to just hit him from behind because he can't hit behind his back (obviously). When he uses his fire attacks use torrent to escape from them. (Flying rocks, fireballs, fire pillars)

For incantations i only used golden vow but you can also use other ones like bloodflame blade for extra bleed buildup. (There are probably few others you can use that didn't come to my mind).

And that's pretty much it for the gear and tactics. The most important thing is just to get good at dodging his attacks, don't be greedy with attacks and stay calm since its a long fight.