The ancient gods are a race of cold, alien, and evil intelligences that exist in non-spacetime of swirling anti-matter "outside" our universe. Dwarfing even Unicron in terms of power, their limitless abilities are checked only by their inscrutable motivations and indifference to the affairs of lesser egregores that grow in the warm and wet hothouse of time and space we so arrogantly call "reality".
Ramjet was cast adrift between dimensions when Unicron's form imploded into a black hole. He found himself in the realm of the ancient gods who repeatedly destroyed and re-created his body from the inside out while toying with his spark. Bored, they cast him back into the universe he had come from. Ramjet then sought out his fellow herald Nemesis Prime and journeyed to the dimension in which Unicron was trapped.
As a result of his encounter with the ancient gods, Ramjet's body was now composed of antimatter held together by the force of his will, he had a permanent connection to non-space, and his body occasionally manifested little... tentacle-things.
- The ancient gods bear a more-than-passing resemblance to the assorted ancient creatures of the Cthulhu Mythos and may actually be those selfsame creatures. It's fair game, after all, since the mythos is in the public domain, and has been incorporated within many other fictional properties.