The equipment is a skinned type of gear, from a faction considered demonic because it’s a different pantheon. In those terms, nothing looks human because the equipment is used to produce a custom shadow armor.
If it then is used by another faction, the design would still remain a shadow armor, or shadow walker. In D3, the creation of custom armor and there respective rings, is one of the more interesting features.
In practical history, a basic armor spell, is required to save real lives. According to historical records. Its a fact no more miraculous, than someone reaching into a straw thatched roof, and drawing a sword from it. Is it a miracle, if it is there when called upon? That depends upon your point of view, turning aside a fatal weapon, or warding away demons in human form. Swords tend to end up dropped into rivers to this day.