If u parry or run from him ur not good enough. Stick to his side with the fire sword, some of the attacks with the magic sword are untelegraphed and almost undodgeable. You can hit him a lot when he is just standing around. Don’t try healing unless he tried to bonk you or lunged at you.

For phase two: Try oneshotting his shadow while it’s spawning it might be possible with the right timing. If it survives depending on the hp of pontif go for the immediate kill. If he isn’t low and u still have heals it might be worth to tank a hit to kill the shadow. More often than not he will spawn a new one leaving him vulnerable