As mentioned before, the Marvel Universe was also a cycle. It began when the First Firmament, the concept of the "universe" itself, died in the Celestials' rebellion. The material universe collapsed into a Cosmic Egg again and again, then exploded again and again, spewing matter from the singularity to form new universes and new Firmaments, because it was the universe itself.
Each generation of Firmament, or rather, each era, further refined the concept of the universe.
For example, the Second Firmament was born from the remains of the First Firmament. It inherited nearly all matter and established the concept of "living creatures."
The Third Firmament was born in female form. She added the concept of the "multiverse" to the universe, or rather, divided the original greater universe into smaller universes for easier management.
The Fourth Firmament created "stories" and "time"; the Fifth Firmament created "magic" and "dreams"; the Sixth Firmament created "science" and "inventions."
Countless creatures had once lived within those Firmaments. They developed and multiplied, writing their own stories, rising and falling along with the changes of the Firmaments themselves.
When the Firmaments withered away, they vanished as well, leaving behind not even stories or legends. There were no humans or Earths in those eras either.
Only a very small number of creatures could escape the multiverse or find a way to survive.
For example, when the Sixth Firmament collapsed, there was still a creature named GaLan within the Cosmic Egg it formed. The Egg protected that creature as it entered the next cycle.
As everyone knew, that creature later became the Planet Eater.
And when that Cosmic Egg exploded, what appeared was not an individual Seventh Firmament. Instead, the rules changed: Eternity and Infinity were divided out first, followed by Death, Oblivion, and Galactus.
They did not inherit