Rewarded after completing wave 76-100 in the Crucible.
|“|| The abyssal spaulders are a portion of the four horseman's Ultimate war-gear. The rider wearing these armored shoulderguards is prepared for any challenge. Few dare to face a Horseman clad in his Abyssal Armor, for it is ritually prepared towards the destruction of all enemies. The spaulders improve every aspect of its wearer's ability in battle, and when combined with the other pieces, the set produces even more powerful effects.|
— In-Game Description, Darksiders II
Also add two purple horns to Death's head.