Upon a break in the Plateau's stone walls a barrier of red energy lies, only allowing those who are Blood Marked to pass through it. It continously ripples with energy, and sometimes appears to almost have living souls trapped in it's glowing mass.
The outer walls hold two large Graeph Hybrids, who are always held to the Plateau walls by red energy chains. They barely ever move or shown signs of life, almost appearing to be real statues. They are, like everything else, a precaution incase something happens to the Plateau. If ever the chains were to let them go, they would go in to a frenzy and kill anything remotely like an enemy in their path.
Every Plateau, or Outpost, has at least two Graeph Hybrids as guardians. While Graephs themselves are fully sentient beings, a Graeph Hybrid is not. Having been mixed with the blood of a Scarg, they have been turned in to feral beasts.
Like the pure Graephs, they too originate from the Outer Dimension.