|Base of Operations:||The Void|
|First Appearance||Last Appearance|
|Ultimates Vol.2 No.1|
First Firmament is the entity first known to as the Cosmic Jailer it is later revealed that it was the very first and original omniverse in the segments of the previous omniverses that occurred once a cosmic event rebirths it for another renewal.
Aeons ago there was a single sentient cosmos and out of it's unutterable loneliness, it wanted to fill this desire and so the First Firmament had created life, this resulted in the creation of Dark Celestial beings they were described by itself to be it's servants and it's toys. As any creation it was some of whom were Industrious in their worship of their god-like creator, and wanted to follow in it's shoes and so this soon started to take shape with them also creating their life in their own image. But only by seeking approval of their creator could they create life on their own, this allowed the First Firmament to give them a name which they now went by Aspirants, but with another group which were multi-colored rebels they wanted their creations to evolve and to gain the power of universes for the universe to evolve with them. To know growth and change and mortality. And as the First Firmament overseeing everything the event was described as madness and sacrilege, the now multi-colored beings were known later to be called Celestials and so these cosmic and god-like beings had rebelled against their creator and their own brethren the Aspirants, so thus began the Celestial War. It was the Celestial rebels that had detonated their unimaginable weapons in their final conflagration, and as this occurred the First Firmament was then shattered into pieces, It fled to the farthest edges of being with it's remaining aspirants inside of it and behind it. and so New universes coalesced, forming a new, collective entity. A second Cosmos-and the first of a new Breed. The First Multiverse.
The First Cosmos had watched from the void as the Celestial rebels colonized the Second Cosmos,the second infinity was colonized by the rebels. Here they had evolved their own servitors--calling them "Omegas" in opposition to the Alpha that was the First Firmament and it was a snub an insult a challenge to it.
The First Firmament had continued to watch them from a far point and as their new reality aged around them like some kind of animal with this it fulfilled their craving for Mortality But with the death of ONE Multiverse was only the birth of another, filling the First Firmament It was writhered in frustration in Exile as the Multiverse was Reborn over and over. Evolving further with each iteration until the current Eternity. 
But the First firmament was stronger it had grown in the Void unlike any other Omniverse Eternity it was whole a single unbroken unit. and it's very weapon was an alien to any iteration its because it had Hate. With this hate it gave it enough patience to choose a moment and it was after its death and resurrection after its change from the Seventh Multiverse to the Eighth when it was weak and was easier to capture. 
But it wasn't enough as this Eternity was just chained and not dead so the first firmament had sent its Aspirants forth it's Astro-Gods, its Dark Celestials to infect it and to infiltrate its timeline to corrupt its inner workings. To damage it wherever and however it could. and everything was in place and now the eighth omniverse was taunted with death.
Not long ago, Earth's most powerful heroes had come together to solve the biggest problems in the universe. These earthlings called themselves the Ultimates and as their first mission was curing Galactus for his need to devour planets which was a success but in the end the members of the team came to blows over Captain Marvel's use of predictive justice. And now the government had shut the Ultimates down. their dream of fixing the universe was apparently killed. It was Galactus who had regrouped these superheroes to help him in his quest for the infinite crimes of chaining the omniverse itself calling them his heralds.
While in the Superflow it was shown that Master Order and Lord Chaos had called a hearing and a trial for the imbalance in the cosmic hierarchy after Galactus now known as the Life-Bringer had punched them out it and so they were all being judged by a now rebirthed The Living Tribunal who heard both sides and made his decision in the favor of Galactus . And so being influenced by the first firmament they had become enrage by his judgement and as the living tribunal cosmic senses were blocked they sneaked attacked him and destroyed his head.
The cosmos barely reborn the tribunal, the personification of Law and Judgement barely risen anew was murdered by the cosmic beings known as Master Order and Lord Chaos under the influence and increased power of the cosmic jailer. It was galactus who sent Conner Sims also known as the cosmic-power herald Anti-Man to warn the ultimates about this cosmic disaster. As Conner went it was then Master Order and Lord Chaos who turned their attention to galactus to force him to start devouring worlds again but he was resisting their influence but then Master order had realized there is no Law no duties and him and his brother went to locate their own creation the In-Betweener where they amalgam into a new singular entity known as Logos 
Logos the newly proclaimed Law and Judgement had went to the last celestials in an attempt to convince them to serve under their original purpose as unknown judges of worlds with Logos explaining that when the Beyonders attacked the previous Multiverse annihilating their race they hid in a deep fold of space-time where they would live. But refusing the celestials attempted to attack this new entity trying to impose onto them and were utterly annihilated by this being other than the celestial known as One-Above-All.  After Logos had nearly killed of the last of the rebels it was Queen of Nevers who saved the last known Celestial explaining that the Beyonders were right that the Celestials were no longer necessary  and with this they ventured back to Galactus and had changed him back into his Devourer Form with an unknown substance.
Events come into play as the living tribunal is murdered, logos proclaiming to be the new law and judgement, and Logos executing the Celestials with Galactus hunger more potent than ever. As the ultimates face off against the Troubleshooters each individual facing off with each other. Until Simon Rodstvow revealed himself to be a Servant of a Higher order that is beyond anything and everything they have ever faced and the end of everything again and just then a Hungerer and a disfigured galactus appeared to them As events further his master reveals itself It imposes to the 8th Cosmos that once it is destroyed it will absorb what's left of it and then it will erase the history of the pass omniverses calling them filthy organisms and that once its goal is completed there will be One Universe,One Reality, and One Totality when it was just it .
The First Firmament, like most other abstract entities, subjectively displays a lack of empathy. This is further proven by his quest to regain absolute control over the omniverse by killing off the cosmos culmination of Eternity (also known as Omni-Eternity). It is also displayed that it has emotions as it hates the Omniverses known as Eternities.
First Firmament at first seemed to be identical to the current Eternity of the Omniverse but it has three blue pupil like eyes and seems to be like any Eternity with the same concept of having space as its main attire with various horns.
Powers and Abilities
First Firmament is probably and currently the most strongest being in modern Marvel history as it is the first Omniverse with powers even beyond that of The Living Tribunal.
- Near-Omnipotence: The first firmament being the first creation he wields power beyond all even those who can manipulate the megaverse such as the now deceased living tribunal with this he has the basic of all cosmic beings but on a beyond level scale of which it can manipulate reality,time,space,magic, and matter far beyond a megaverse power scale.
- Near-Omniscience: the first firmament isn't fully omniscient as he hasn't shown any knowledge of future events but only to the past and present events.
- Omnipresence: first firmament being the totality of the cosmos he is omnipresent by default he exist anywhere be it existing or non-existing be it if its inside or outside of himself he will always exist.
- Cosmic Awareness: First firmament can sense things unlike any other as it can sense cosmic dangers within his own body.
- ↑ Ultimates 2 Vol.2 No.6 Page 19
- ↑ The Ultimates Vol.1 No.1
- ↑ Ultimates 2 Vol.2 No.6 page 4
- ↑ Ultimates 2 Vol.2 No.6 page 5
- ↑ Ultimates 2 Vol.2 No.6 page 6
- ↑ Ultimates 2 Vol.2 No.6 page 7
- ↑ Ultimates 2 Vol.2 No.6 page 8
- ↑ Ultimates 2 Vol.2 No.1
- ↑ Ultimates 2 Vol.2 No.2 page 5,6,7, and 20
- ↑ Ultimates 2 Vol.2 No.3 page 21
- ↑ Ultimates 2 Vol.2 No.2 page 8
- ↑ Ultimates 2 Vol.2 No.3 page 20
- ↑ Ultimates 2 Vol.2 No.3 page 21
- ↑ Ultimates 2 Vol.2 No.4 page 4 and 5
- ↑ Ultimates 2 Vol.2 No.3 page 5
- ↑ Ultimates 2 Vol.2 No.4 page 19
- ↑ Ultimates 2 Vol.2 No.4 page 20
- ↑ Ultimates 2 Vol.2 No.4 page 21
- ↑ Ultimates 2 Vol.2 No.5 page 6-13
- ↑ Ultimates 2 Vol.2 No.5 page 18