The Black Shield (Interfectus shield)

 

“The Interfectus is a demon which wears its shadow skin as armor. There is a spot on its ankle which is essentially the boundary between two plates of armor, and that is where I struck. I snapped the plate of armor and made a shield from its skin.” 

In the Interitus series, a black shield (sometimes called an Interfectus shield) is a completely-impenetrable shield, capable of blocking any attack. It should be noted that the shield protects its user from damage but not from knockback; a heavy strike will still send them stumbling backward. That said, the black shield is ironically the only thing in Agrideī that can withstand a strike from an Interfectus. It is the primary defensive weapon of Lazaro (see: Lazaro), but it is passed between his allies as they defend ordinary citizens from Interfectus attacks. Lazaro claims to have struck the shadow demon between its plates of armor, and this let him snap off the armor plate without breaking it. He has carried the weapon ever since.

It should be noted that it is possible (although extremely difficult) to damage the armor on an Interfectus. The reason for this is that its armor (made of this black shield) must be bent and curved to fit the surface of the monster. This bend weakens its structural integrity and causes it to be slightly more pregnable than in its detached state.