Father Ariandel is a large, deformed corvian covered in feathers, with long black hair and a decayed face, similar to other corvians. His head is disproportionately small by comparison to his body, and his limbs are long and thin. He has a deep Scottish accent. Before unlocking the path to him, the sound of him striking himself with his flail can be heard at intervals.
He is bound and tied to a chair where he sinks his head inside a large Lordvessel-like bowl, which he uses as a weapon.
Father Ariandel is the keeper of the Painted World of Ariandel, thought to have been the most recent one to restore it after the Painted World of Ariamis rotted away. When he met the Unkindled Sister Elfriede, she convinced him to forgo the destruction of his rotting world, and to stifle the flame that would burn it to be replaced by a new world by the next restorer, choosing to rot together 
He constantly flails himself, bleeding onto the flame, to prevent the fire from burning his world, for he used blood in the restoration, and only that blood could prevent the fire from blazing again. When Friede's blood flows to the bowl containing the flame, the sight of her corpse enrages Father Ariandel, causing him to break free and strike the bowl against her unkindled blood to spark the flame and revive her by restoring her ember as an unkindled.
Once he dies, he declares the prophecy of the two ash and the flame fulfilled, and even after they both die, it stays burning strong.
Father Ariandel is located in the Painted World of Ariandel, inside the Ariandel Chapel. He can be accessed by turning a wheel in the insect pit underneath the chapel, which will activate a contraption revealing the passage near Sister Friede, where he is held.
- Note: Ariandel will fight the player in the second phase of the Sister Friede boss fight, so for a more detailed analysis check the Sister Friede page.
Ariandel is very aggressive, but he is not particularly fast, although he deals massive damage with his bowl and can crush the player with his legs when he charges forward. He also has a variety of fire attacks at his disposal.
He can be staggered and riposted after enough damage has been dealt to his arms.
|Upon entering the arena||"I see flame, flame, flickering, once again.|
Not enough blood yet shed.
My flail... Bring me my flail.
Ahh, Friede. What stops thine ears?
Please, my flail, right away..."
|Interact||"Ahh, oh. Bring Friede to me, please.|
Canst thou not see?
The flame, flickering once again.
Soon will it surge. I can see it, feel it..."
|Third phase transition||"When the Ashes are two, a flame alighteth.|
Thou'rt Ash, and fire befits thee, of course..."