Hey, first of I'm new to the lore thread, and I have not completed 2.4 main story, the 2nd or 3rd coils or all of the primals EX (excluding Garuda) and I never played 1.0 so a lot of my info and speculation may be way off or completely wrong.
To start off here is what I have found out so far:
Primals
-Beings of aether summoned through an abundance aether and prayer.
- Odin, a primal of a warrior who changes form into the last person who defeated him.
-Great King Moogle Mog, a being of aether summoned in a similar manner to primals, even though he was not a primal (at least before his summoning) and simply a legend among moogles.
-Egis, a smal part primal summoned by Summoners to help them in combat.
-Their purposes: to defend or fight for those who summoned them.
-Need continuous aether and prayers to remain in the mortal realm (most likey reason why they temper mortal).
-Primals with enough aether can summon lesser aspects of themselves like Suparna and Chirada, and egis.
Crystals of Light and Darkness
-Crystals are the physical manifestation of aether, when there is an abundance of aether in the area.
-Hydaelyn, Crystal of Light, controls the lifestream and grants the power of echo to her chosen mortals.
-Zodiark, Crystal of Darkness, Ascians, possible controls a different aether/lifestream.
-Hydaeyn is able to exert her power through the Elemental Primals crystals (as seen in the fight with the Ultima weapon).
-Zodiark seems to have been sealed or banished from the world of Hydaelyn.
Bahamut
-Non-elemental primal of dragons.
-His core/heart seems to be a crystal of darkness.
-Elder primal.
-Able to manipulate the flow of aether.
The Twelve
-Able to be summoned like primals.
-Associated to elements like most primals.
-Summoned at The Battle of Carteneau as their symbols.
The Void
-Ascians have summoned voidkin to fight for them before.
-Voidkins aether is rejected by Hydealyns lifestream.
Conclusions and Theories
-Primals and gods are the prayers and belief of mortals given form through the aether.
-Mortals existed before primals and "gods", their life springing form the Aetheral Sea (gonna call it that for short since life in this world sprang from the primordial sea and it's easier than saying the pool of aether at the start of time)
-Hydaelyn and Zodiark were the first forms given splitting the Aetheral Sea into to their two lifestreams and aetheral realms.
-Voidkin are possible a part of Zodiarks lifestream hence why their aether is rejected from the world now that Zodiark is sealed or banished from it.
-Primals we have faced are created from the aether from Hydaelyns aetheral realm. Bahamut (and possible Odin) are created through aether from Zodiarks aetheral realm. (Just read a post saying Bahamut was killed at Carteneau and was re-summoned by Dalamunds fragments so this is unlikely, still leave it here just in case).
-The Twelve are the same beings as primals given different form and purpose through differing prayers and belief of the people summoning them.
-The Ascians are making the Warrior of Light stronger in order to defeat Bahamut in order to re-establish a link between the world and Zodiraks when the enormous aether Bahamuts composed of tries to return to Zodiarks aetheral realm (once again unlikely due to Bahamut having died once at Carteneau, however Bahamut may be powerful enough that even the smallest connection (which the Ascians seem to use) to the world is enough for him to be summoned, and killing and re-summoning him may widen that connection).
-Similar to how Hydaelyn stops the Warriors of light aether from returing to her aetheral realm, Zodiark does the same for the Asciens, however because he is no longer connected to the world they exist in the space in between, possible meaning they are Warriors of Darkness.
-The Aetheral Sea was conscious (at least enough for memories from the beginning to remain in the aether) and neutral showing no aspects or all of them (because Ramuh metions he (a being of aether) remembers a time before light ane dark). Hydaelyn and Zodiark have multiple aspects, Light and dark, Life and Death, Creation and Destruction. The primals are smaller aspects of Hydaelyn and Zodiarks aether, the Elemental primals are a part of nature therefore a part of Hydaelyns life and creation aspect. Bahamut could be a part of Zodiarks aspect of death and destruction.
-Elder primals are primals that have not been seen for a very long time, either because they are sealed or trapped in Zodiarks aetheral realm.
-Another possibility is that Elder primals are (in a kind of primal/God hierarchy) between Hydaelyn/Zodiark and lesser primals this would explain how Bahamut is able to control the flow of aether like how Hydaelyn controls the lifestream (possible why Odin does not need people to gather crystals for him to be summoned).
Well that's it thanks for reading, like I said I am new to the lore thread and may have missed some important facts, feel free to correct or debunk my theories.
*Edit
Men Among Gods
-When fighting Odin he says: "Here I stand--a god amongst men. Yet here I remain--a mere man amongst gods".
-Louisoix gain becomes the Primal Phoenix after gaining an immense amount of aether (and possible prayers of the people wishing to be protected from the fall of Dalamund and Bahamut).
-Shiva, originally a mortal woman condemned for sleeping with a dragon, this act led to the heretics venerating her as Saint Shiva.
-Good King Moggle Mog XII, a legend among the moogles of their king who lowered his subjects to the lands of the mortals when war erupted in heaven. (Most likely only an legened at that there was no original Good King Moggle Mog XII, I'll leave it here just in case).
Birth of primals theories:
- I believe that primals are created through strong worship and belief in things as stated in the theories above. The would elemental primals are born of worship of the natural elements and forces of nature.
-Also I believe that mortals can attain primalhood?/godhood? through enough worship and aether, the three prime examples being Pheonix, odin and Shiva. How this is possible is because mortals souls/life-energy comes from the aether so with the collection of enough aether or rejoining the lifestream and the prayers of mortal they can become primals. Why I don't believe all primals to have once been mortals is because Ramuh states he remebers a time before man.