*SPOILER* So I think the new primal in 3.5 part 2 is...

[Nestama]

I highly doubt it's Shinryu, especially since it should technically already exist (void/rift hopping wyrm God). Omega is probably not even Allagan tech. Shinryu will probably be the final boss of Stormblood's 8-man raid. Or penultimate.

[ADVSS]

Pretty sure Omega is allagan tech

[Anonymoose]

That's exactly what I'm not so sure of... We have no proof at all that anything is drawn from the lifestream...

As has been mentioned in past quests, most primal summoning comes down to the faith of the primal's followers. That faith acts as a beacon for the primal's dispersed aetherial essence, allowing for the remanifestation of a being whose infinite number of parts were tossed into that giant blender known as the Lifestream. If enough followers of Bahamut (or perhaps Dalamud, which, ultimately is the same concept) were to gather and perform a summoning, then technically anything is possible (with the proper amount of aether to act as the catalyst), and it doesn't necessarily need to be on Meracydia (which, in many places is still a smoldering waste, even today). What needs to be understood is that the state of the believers when the summoning occurs directly affects the manner in which the dispersed essence of the deceased is reconfigured. Tiamat, knows of this first hand due to her failed attempt to resummon her fallen beloved. She and Bahamut's brood knew Bahamut better than anyone, but since their hearts were darkened by sorrow stemming from the loss, coupled with hate directed towards the Allagans, the Bahamut that was ultimately brought back ended up being naught but a twisted shell of the dragon Tiamat remembered. This also explains the differences between the actions and temperaments of other primals spanning from 1.0 to 2.0. The needs and desires of the believers doing the summoning changed following the Calamity, resulting in changes in the primals they summoned, Ifrit and Titan, even Shiva all being good examples (though Shiva's differences span back further than just 5 years ago).

Garuda the general has for long been in the lifestream, so I'm not so sure her soul could come back so easily from the dead...

If the above is accurate, and what we might call "typical", it seems as though the uncountable pieces are just drawn to the beacon by virtue of having once been together in the thing that is in some way or another the object of faith. It doesn't seem as though the distributed essence is aware of what is happening, and by the time it's rematerialized it's something new entirely. The original essence as it was might already be gone forever (perhaps barring rare circumstances were it wasn't completely shorn apart in the first place).

[ArcaviusGreyashe]

I never read this post from Fernehalwes, so thanks for quoting it here ! (And, just to be clear, I'm not being sarcastic, here, I really like to be corrected when it's justified)

So yeah, I admit my mistake : there is a beacon. So, if what Ferne said is true in all cases, Rhalgr did exist at some point (And that means Sophia, Sephirot, Zurvan and every other as well). But that makes me even more curious of who they were. But I guess we'll never truly have an answer for most of them...

Still... I'm not so sure that's the only way of summoning a primal. Granted, this might be the "typical", as you put it, way of summoning a primal, but... Did Phoenix exist as well ? I mean, I think we can all agree that Phoenix was a primal as well, but I don't recall any kind of reference to him in any way before his summoning. Since 3.5, you can maybe argue that it was a Firebird, but it seems... kinda off for me. It's open to debate, though, I just have a reasonable doubt about it being the only way to summoning a primal.

Yet, if we overlook that doubt and accept it anyways, I think there's still a way for summoning Rhalgr without him having existed. We don't know much about Ilberd, except the fact he still is a fervent defender of the mhigan cause. He was a child, when Ala Mhigo fell, so it's likely that he was admiring some of the warriors that protected his and the other exiled mhigans' escape to the point of revering them. So maybe his idea of Rhalgr is that of one of the men that enabled them to flee Ala Mhigo, so that would be the soul he'd call back from the dead.

I'm not saying that's what happened in any way, here, it's likely that Rhalgr and the other twelves existed (I mean, why not ?), I'm just saying that maybe we should be cautious with this. The extent of the "reconfiguration" isn't so clear, given how Garuda doesn't look like an allagan (and doesn't fight like one either), and how Bahamut was different from his former self. So could a simple soldier (or even a fatherly figure for Ilberd) be transformed, by this very reconfiguration, into a god-like creature ?

Aside from that... The aetherian remnants that are collected by the summoning, are they simply the remnants of the being that's being summoned, or can they be the remnants of the last incarnation of the primal ? There are still many questions, and you might disagree here, but I think that though Ferne's answer is really interesting and enlightening, we still have many things to learn.

[Nestama]

Pretty sure Omega is allagan tech

Then would that make the Omega in XIV unrelated to the other Omega's in the franchise? or would XIV be its origin?

[Belhi]

Then would that make the Omega in XIV unrelated to the other Omega's in the franchise? or would XIV be its origin?

Unrelated. Omega was a weapon created by the Allag to counter Bahamut, the primal version.

[Nestama]

I'll have to rewatch cutscenes, as I'm still unsure if it's said it was made by the Allagans, or just used by them.

[Anonymoose]

I really like to be corrected when it's justified

Ditto! Nothing worse than incomplete notes and fanon. (Aside from being told you're wrong based on another opinion, I guess...)

But that makes me even more curious of who they were.

I just mind the [May Not Be Typical] sign and hope to stumble across the backstory one day.
Doesn't stop me from making up baseless headcanon in the meantime, though.

Did Phoenix exist as well?

No idea! They seem to be content to leave the explanation where it is for the time being. Perhaps they do so because it's such a wonky case, with Louisoix literally becoming (as far as we've been told: not summoning, not becoming host to, just becoming) a primal on the spot. With nothing better to go by, I like to think that people prayed for Louisoix to save them, and the Phoenix's physical form came from something on his mind at the exact moment all that free-floating aether resonated with the focused prayers and overtook him. In such a case, he would be the primal, but the shape came from him seeing a world in flames, desperately wishing for it to be reborn from the ashes, and thinking back on the legendary phoenix as any scholar might. Much like how Garuda is a woman who has been warped into a bird-woman, Louisoix would be a man warped into a bird-period, lol.

Another reason they might be leaving it mostly alone is because any specifics open a dangerous door. If Louisoix is the primal (and is not host to a third-party presence, which he did not seem to think was the case), and we never actually saw Louisoix die, then it's possible that he wasn't necessarily re-materialized ... he was metamorphosed directly from living person to aetherial deiform. How many people are now praying for the Warrior of Light to be their salvation? That could be a massive liability, and a hell of a way to die.

That said, yeah, I don't see it as impossible that something that would identify as Rhalgr could come from this.

Wouldn't it be the troll of the century, though, if the scheme was just to reconfigure Lahabrea from the Eyes?

(DISCLAIMER: Not claiming this has any probability. Please don't all dogpile me like when I said "Gaius might not be dead," lol.)

[ADVSS]

Then would that make the Omega in XIV unrelated to the other Omega's in the franchise? or would XIV be its origin?

Possibly its called Omega Weapon right? Omega is just Omega

[Fevelle]

Possibly its called Omega Weapon right? Omega is just Omega

FFXIV Omega is just Omega, at least it's completely based on FFV's Omega design, not FFVIII's Omega Weapon.