Blasphemous

The first phase is easy, but if you got unlucky he summons fireballs. It happened with me. The worst case you need to use 2-3 health potions, but still you are good to go as long as you have Debla of Lights.
For this prayer you need to finish Lvdovico's quest. Basically bring 3 items for him.
Here a video (its not mine):

Now comes the harder part. You need to attack the flying sword's eye. If you deal enough damage Escribar's face uncovered and you can attack it for some time. Now its time to use Debla of Lights just underneath it. I used 4 times before the face disappeared again. If you have enough fervour you can kill him instantly or if not nearly kill him! Repeat the process and he's dead. With this method I killed him 3rd try!
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Tip: if you died, when you enter the second phase don't pick up your guilt fragment immidiately! Use Debla until your fervour bar almost empty, then pick it up!