Zilvra

Zilvra is an unusual substance introduced in Eye for an eye. It was kept secret from the other Fears by Mister Oculus, who claims the substance represents justice and good, and that Transgression tried to destroy it to increase her power. Its power apparently turned Transgression's right eye into Mister Oculus. Mister Oculus' blood contains Zilvra, which may be how he gained a mind of his own.

It is the opposite of Azoth and can be controlled by Iris Dogood, similarly to how Slender Man controls Azoth. She can make it change shape, move with her, and more. Unlike Azoth, it is capable of entering people's bloodstream, and only a few humans can control it. Like Azoth, it is implied to have a level of sentience.

The origin of the substance has yet to be explained or questioned.

Trivia

 * Azoth starts with an A, the first letter in the alphabet, while Zilvra starts with a Z, the last letter in the alphabet, making them on opposite ends of the alphabet, as well as being opposite in nature.
 * The name originates from the word "silver."