The Nordic God Odin is known for sacrificing one of his eyes as a means to gain more inner knowledge. He believed sacrificing some vision sensation would enhance his intuition, or something like that.
I wonder if that is what the cabal is doing with their black eye marker.
They could not all go around with one eye actually missing, so they get a black eye as part of the initiation, believing that it will enhance their understanding and wisdom.
And his companions were wolves!
https://en.wikipedia.org/wiki/Odin