A Shield made larger than usual inorder to protect the wielder. The black steel was used in order to protect the wielder and others from the abyss.

Shields require the Utilize action to Don or Doff. You gain the Armor Class benefit of a Shield only if you have training with it.

Notes: Bonus: Armor Class, Resistance: Bludgeoning, Piercing, and Slashing from Nonmagical Attacks, Bonus: Shield AC on Dex Saves, Combat, Warding