Given their extremely long life span, it was inevitable that the population of the planet
Rigel would come to realize that at some point their numbers would begin to threaten their existence due to the finite space available on their world. And so they turned to colonization of other worlds in order to survive--and in time, that pursuit became their preoccupation, eventually leading them to Earth where one of their operatives,
Tana Nile, laid claim to it. It was the
intervention of Thor which foiled that plan, and, in so doing, led to the confrontation of
the menace of Ego in the bio-verse of the Black Galaxy which the Rigellians feared would expand to engulf their own planet.
It was the encounter with Ego which inadvertently led to the Rigellians' attempt to use that being's unique properties to evolve heretofore unsuitable worlds into habitable planets that would ensure enough space for their ever-growing race in perpetuity. Yet that effort ended in disaster--and, months later, the Rigellians' greatest fears were realized when their home world was destroyed by the approach of the Black Stars (a coincidental play on words in light of their past dealings with the Black Galaxy), leading the Rigellians to undertake the most massive evacuation in their history in spacecraft that collectively housed nine billion of their people in close quarters. For a pioneering race, such a fate no doubt amounted to living their worst nightmare.
Which brings us to a six-issue arc of Invincible Iron Man from 1978, written by Bill Mantlo and featuring art by Carmine Infantino, Keith Pollard, Fred Kida, and Alfredo Alcala, which begins with the discovery of the Growing Man on Earth:
And since the Growing Man's former master, Kang, was believed to be deceased at the time, the search for its point of origin leads to the moon (thanks to the calculations of the Jack of Hearts, whom Iron Man has agreed to take on as an apprentice), where Soviet super-agents had previously arrived to investigate signals being emitted from a mysterious egg-shaped object now present on the surface.
When the same piercing sound that downed both their craft reoccurs, Iron Man and the Jack of Hearts race toward and penetrate the object, which transports them into deep space and a confrontation with Rigellian colonizers of unknown intent who react preemptively.
Uh oh--it seems Mr. Pollard has joined the ranks of Messrs. Buckler, Frenz, et al.!
Anyway, since Thor had no difficulty escaping from his own Colonizer-induced proton particle casing...
...Iron Man proves he's no slouch at the task, either, as we arrive along with himself and his card-motif companion at this story's third installment--hopefully to learn just what the Rigellians are up to!