The Dark Wanderer is the Warrior from Diablo who has been possessed by titular demon, the very demon he sought to contain within himself. After finally engaging Diablo in a duel in the depths of the hell beneath Tristram, the Warrior defeated and killed the Prime Evil. However, by this time he had been thoroughly corrupted by the demon's influence, and was led to believe the only way he could contain the Lord of Terror was by placing Diablo's foul soul within his own body, inserting the Soulstone in his forehead.