"Nothing makes a better weapon than a beast let out of its cage, unless the wielder is the one who caged it." This is truest of all of the Great Ones. The Entity Supreme has made sure of this first-hand, for he was the one who released them and made them an offer they couldn't refuse, namely to fight with him against the Atlakans. Problem was they were just too big to be used as weapons. Somme of them were way too volatile and wild to even let out completely. So what the Entity did was create empty suits of customizable armor for some and inhabitable portals for others.
The O'ranbur automaton was built using the same basic structure, only reinforced, and the power transmition only goes one way. The thing is the inhalation of the Great One known as Azathoth's essence was enough to mutate the machine itself. Regardless of the canges made, the O'ranbur now serves its purpose even better. It not only acts as a body, but it also can be used to created a gateway to the Great Ones' prison in order for Azathoth to personally peek through.
Now the O'ranbur is the Entity's favorite means of instilling fear. For that gateway does go both ways, not that it has to. Anyone unfortunate enough to look at Azathoth will be taken to such new depths of fear and insanity that his mind might has well have been ripped to shreds.