This being seems to take the form of the Heavy from tf2. What this monster lacks in wit, he makes up for in strength and abilites.
It is able to drain the ammo and health of players and able to tank damage very well. The only plan is to run.
Taking the form of the Gman, he seems to be less of an active threat to the player than The Behemoth. This doesn't mean that he poses no threat, I've been attacked by him before. To few, he is known as the Betrayor. The reason for this I do not know.
A thing about him is that he appears to have control or "own" a vast location that seems to be out of bounds. The void is a very large connected area that is cloaked in darkness constantly. But I think that maps are able to be converted into this dimenson if he wishes