Knight Artorias, also known as Artorias the Abysswalker, is a boss in Dark Souls. He is exclusive to the Artorias of the Abyss DLC.
Sir Artorias the Abysswalker was one of the Four Knights of Gwyn. He only makes an appearance in the past, as he is deceased by the time the Chosen Undead escapes the Undead Asylum.
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 encountering them in the colosseum of Oolacile.
Powers and Stats
Tier: Low 7-B
Name: Artorias, the Abysswalker
Origin: Dark Souls
Age: Thousands of years old
Classification: One of the Four Knights of Gwyn, the Abysswalker, Founder of the Abysswatchers
Lifting Strength: Class M+ (Comparable to Dragonslayer Ornstein)
Striking Strength: Small City Class
Stamina: At least Superhuman+, likely higher (Capable of temporarily fighting his way through the Abyss, and is amped by it by the time he fights the Chosen Undead)
Range: Extended melee range with his greatsword
Standard Equipment: His greatsword, greatshield and armor
Intelligence: Skilled and experienced combatant before being driven mad by Manus, leaving him an insane berserker
Weaknesses: Driven insane by Manus and the Abyss, his dominant left arm is broken (Though this hasn't been shown to significantly impede his combat skills)