Faraam could have been a normal human who was immortalized by legends through his fighting prowess, as Evlana, Goddess of the Hunt, was actually just a brave hero who was skilled with a bow.Furthermore, Nahr Alma is not only the God of Blood, but also war.
By the time the Chosen Undead encounters him he is shown to have already been corrupted by the Abyss: the reason for his armor's putrefied appearance and the aura of darkness that it oozes. His crippled arm is likely the result of Artorias halting the spread from devouring his wolf companion by means of a now missing shield. He possesses a greatsword that has also been consumed, yet is still far from ineffective. Having lost his sanity, the knight moves about in an untamed manner as he howls beneath the blue shroud of his helm.
Knight Artorias wore distinctive armor, as well as the Wolf Ring, and brandished his Greatsword and Greatshield. He is known to have been a friend to Alvina of the Forest Hunter covenant, and Sif, the Great Grey Wolf, was his companion, who now guards his grave and keeps the Covenant of Artorias ring in his possession.
Artorias hunted the Darkwraiths and was able to traverse the Abyss with the power of his ring, which he obtained after making a covenant with the beasts there, preventing him from being swallowed by the void, but cursing his sword in the process. In recognition of his actions, he was awarded one of Anor Londo's treasures - a Silver Pendant that allowed him to repel Dark sorceries.
When Oolacile became threatened by the Abyss created by Manus, Artorias and his wolf companion, Sif, arrived there in an attempt to save Oolacile and rescue the abducted Princess Dusk. However, the two were overwhelmed, and Artorias sacrificed himself to protect Sif using his Cleansing Greatshield, erecting a barrier around the young wolf. Swallowed by the Dark, he became corrupted along with his already-cursed sword.He was then laid to rest by the Chosen Undead after their encounter in the coliseum of Oolacile.
His legacy as a hero lasted for centuries. By the time of Lothric, there was the Undead Legion of Farron, who were commonly called the Abyss Watchers. They partook of wolf blood, and it is said that their souls are bound together and are one with the soul of the "wolf blood master", most likely Artorias. Wielding greatswords modeled after his, and fighting in wild ferocious styles, the Legion fought a veritable war with the dark of the Abyss that their master had fought ages past