Pontiff Sulyvahn is found near the end of Irithyll of the Boreal Valley and is not for the faint of heart. The developers have actually placed 3 possible NPC summons here, if that gives you any idea to the difficulty of this boss. It is sure to give you hell the first time through. For this fight you will want a shield with good stability and fire resistance and anything that increases the speed at which you regain stamina. You will need to use a combination of blocking and rolling to withstand the aggressive onslaught that this boss continuously brings at you. No judgment here if you die several times, that is to be expected. Because his combos are hard to learn, vary in length and are random, the best advice I can give for phase one is simply roll as much as you can.
If you don’t know how long his combo is, just keep rolling until he stops attacking, hit him once or twice and then roll some more. If you stamina is low, back away and put your shield up the second you don’t know what he’s about to do. Once you get him to half health, phase two will begin with him kneeling and sprouting wings. You can hit him here, but he will do an AoE within seconds that will take half your health so I’d advise against it. Very shortly after this phase begins he will hold his sword up in the air and summon a clone. You want to run in and burn that clone down as FAST AS YOU CAN. I actually thought I had killed the clone here as he had no health left on his bar and vanished, and it nearly got me murdered shortly after.
Don’t do that and make sure he is dead. With the clone dead, the fight is relatively the same except he will add some new moves. He has a couple aerial attacks that you can easily dodge and then hit him as well as a couple ranged beams you need to look out for and roll through or to the side. Keep an eye out, as he will try to summon another clone again and you won’t want him to successfully pull that off. Watch for that sword going up and get in there and burn it down, finishing off the boss in the process if you can.
As found on Youtube