Ask a simple question, get a simple answer: Vampire

[Baaldam]

I feel as though that information might be superseded a bit when we've got descriptions of covenants in Kindred Beijing with names such as Bureaus of Childer and Silence and they've got two covenants influenced by Rites of the Dragon but are not properly part of the Ordo Dracul.

Uncertain. There being a presence of the "core five" in places beyond the Americas or Western Europe does not on itself preclude the existence of other covenants as local, regional or continental powers. Who's to say the Circle of Crone does not draw support from undead patrons of a thousand sects across eastern asia, africa, oceania and parts of south & central americas?

That said, the point about the global West is well made when I had forgotten how Athens is stated to be home to numerous uniquely Greek Covenants (such as the combination Appolonian-Byzantine Christian cult) in addition to the Circle, Lancea and Ordo, with no mention of Invictus or Carthians. Or how in Berlin, a covenant from the communist half of the city absorbed most of the Carthians upon unification. It kind of seems like only North American cities are presented as having the vanilla Covenants.

I suppose what I'm getting at is that while I find this presentation extremely intriguing and inviting for world building purposes, I'm a tad frustrated that the book's overall presentation precludes having set it up or giving it context. At least as far as I can tell.

A few years ago i shared ST duties in a game centered on Rio de Janeiro, a city that (in our fragmented, personal, patchwork take of its history) while dominated by disputes between Crone, Sanctfied and to a lesser degree dragons, has, much to the chagrin of both religious covenants, a quite thriving underground of shadow cults & bloodlines of a syncretic character where sometimes the teaching of Cruac, Theban Sorcery and stranger things will mix and meld in a strange melange of manners.

[Tessie]

So, the implication I get from the settings chapter of the core book is that the five "main" Covenants are mostly just the ones that are really big in the Western world (with the likes of the Lancea et Sanctum and Ordo Dracul having some agendas to proselytize), and that other parts of the world have entirely different Covenants emerging from their cultural context which are just as big.

Is that on the money? Is there a more direct reference to that in a later book? Or even in a part of the core which I've missed?

Depending on who you ask and when you ask you're going to get answers that vary quite q bit because the role of the main five Covenants have been developed and reinterpreted several times by various devs and writers during the production of VtR and both of its editions.
They were created as five archetypal organisations that could be applied literally anywhere without necessarily having anything to do with their equivalents in other domains. Then the Covenant books introduced the concept of local/regional variations within the Covenants while also cementing them as discrete organisations with histories. Later first edition supplements and various Dark Eras for second edition expand upon their origins as well as describing preceeding Covenants, which heavily informs how they could have spread (though with modern travel and communication it's become much easier to spread them further, potentially globally).
How other Covenants relate to the main five still varies quite dramatically. Sometimes they're basically carbon copies with a cultural twist (closely following the idea of the five main Covenants as archetypes) while others are completely new with their own ideologies, roles and advantages.

What can be said for sure is that the big five originated in Europe and naturally spread to the Americas, and that other regions (and earlier historical periods) have/had their own Covenants. But in modern times when the main five can spread much easier it's fully up to the creator of the setting (be it a writer for a supplement or the ST of a campaign) to either create whole new Covenants, use the main five as blueprints, and/or just straight up use the main five. All approaches are supported.

[Horodrigo]

What happens to someone suffering the Soul Loss condition if they get Embraced?
Also, since it's possible to posthumous Embrace someone, is the soul a necessity for the Embrace to happen in the first place?
Final question, what happens to the Soul (the disembodied one) after the Embrace?

[Satchel]

What happens to someone suffering the Soul Loss condition if they get Embraced?

Assuming it takes, they've traded a theoretically reversible condition for a largely irreversible one.

Also, since it's possible to posthumous Embrace someone, is the soul a necessity for the Embrace to happen in the first place?

Open question, but probably not. Vampires have souls as the setting's primary experts on souls recognize them, blood can do a lot in this horror setting, starting Humanity explicitly doesn't map to former Integrity, and the Strix can Synthesize a corpse into a Kindred vampire that does possess Humanity.

Final question, what happens to the Soul (the disembodied one) after the Embrace?

Whatever is most interesting for your game. Normally it's gone at the moment of death, which doesn't seem to stop post-mortem Embraces from producing largely normal vampires who have souls that can be stolen by Tremere or consumed through diablerie.

[Tessie]

What happens to someone suffering the Soul Loss condition if they get Embraced?
Also, since it's possible to posthumous Embrace someone, is the soul a necessity for the Embrace to happen in the first place?
Final question, what happens to the Soul (the disembodied one) after the Embrace?

Note that Tremere doesn't say vampires have souls. Tremere says vampires have something which fills the same functions as a soul, but unlike mortals, mages and deviants, they do not call it a soul.
The mention of deviants is especially noteworthy in this. The sidebar in Nameless & Accursed is written to explain what Tremere could feed on so it would be easy to assume it would either call everything the Tremere could feed on souls, or everything they could feed on that aren't mortal/Awakened souls (since those two are special for ideological reasons) functional substitutes. Instead, vampires have functional substitutes the Tremere can feed on while deviants have actual souls but so broken they can't be fed on, strongly implying that whatever vampires have is the soul twisted to being unrecognisable (moreso than the souls of deviants), or they gain something else entirely.

Considering that killing the victim is the first step of the Embrace (feeding the corpse some Vitae being the second) as well as the prevalence of Posthumous Embraces (i.e. where the second step simply takes place after some time, I've always argued that vampires don't have souls. With the news in Nameless & Accursed I revised this stance to assume that whatever they have is not the original soul transformed by the Embrace but something new. Hence, Embracing someone without a soul should be completely possible.

But as a last note I want to add that, while I'm pretty sure my interpretation on CofD soul metaphysics is the most reasonable interpretation, it's all still based on information from MtA rather than what makes for an interesting VtR game, and thus it's only relevant in your game if you're highly invested in adhereing closely to the "canon setting" as much as CofD can be said to have one. In our current vampire game the soul is absolutely necessary for the Embrace because it provides "fuel" for the transformation and the development of the first dot of Blood Potency. Someone who's soulless would probably become a Revenant or possibly even a larval if they can get Embraced at all. (The soul is also what transforms into ghosts in our game, which is absolutely not how it works in CofD as GtSE is quite explicit about. Hence a human can either leave a ghost or be Embraced, but not both barring exceptional circumstances.)
What I mean is, fuck the canon unlesd you're just theorycrafting, and do what's best for your game.

Edit: Almost forgot about diablerie. The thing is, the fluff around diablerie is written fully from the perspective of the characters. It says diablerists are convinced of the existence of the soul, but the truth is that the effects of the diablerie doesn't really align with what is known about souls in general. Maybe diablerie is the consumption of the vampire's soul substitue (see N&A), or maybe it's something else entirely. I mean the primary effect is getting special XP based on Blood Potency and a Discipline dot. The equivalents of a mage would be Gnosis and Arcana, neither of which is part of their souls. The soul is necessary for using the Arcana, but pop in a human's soul and the mage will still regain their original powers. If the same is true for vampires (about where the BP/Disciplines are located, I mean, not the part about popping in a human soul although that is an interesting question), then you'd be able to perform diablerie on soulless (or soul-equivalent-less) vampires (perhaps after a Tremere has stolen it).

[Satchel]

Note that Tremere doesn't say vampires have souls. Tremere says vampires have something which fills the same functions as a soul, but unlike mortals, mages and deviants, they do not call it a soul.

Is this from somewhere other than Nameless and Accursed? I can't find anything making a distinction.

[Tessie]

Is this from somewhere other than Nameless and Accursed? I can't find anything making a distinction.

I forgot. Dave Brookshaw wrote a whole list on Discord, but the wording in N&A is completely different.
Here's the post (if I can get this to work on this forum):

[Horodrigo]

Does a souless person still produces Vitae normally for Kindred?
I'm asking because for a Strix, a Souless person does not produces Vitae from Breath Drinking.

[Satchel]

Does a souless person still produces Vitae normally for Kindred?
I'm asking because for a Strix, a Souless person does not produces Vitae from Breath Drinking.

I'd say so, given the other differences between blood-bound Vitae and the stuff the Strix are made of.

[Tessie]

I'd say no because both Kindred and Strix drain Vitae that is interchangible for all purposes where its medium isn't relevant (i.e. non-blood Vitae can't be spillt; this logistical difficulty is shared with ghouls who have blood Vitae but no means of spilling it themselves). I assume that since both fuel traits share the exact same name and are used for the same stuff at the same rates, etc, actually is the same stuff, and the text about blood Vitae is pretty clear that the blood is only a medium for the Vitae rather than being what Vitae consists of.

[Neos01]

I'd say no because both Kindred and Strix drain Vitae that is interchangible for all purposes where its medium isn't relevant (i.e. non-blood Vitae can't be spillt; this logistical difficulty is shared with ghouls who have blood Vitae but no means of spilling it themselves). I assume that since both fuel traits share the exact same name and are used for the same stuff at the same rates, etc, actually is the same stuff, and the text about blood Vitae is pretty clear that the blood is only a medium for the Vitae rather than being what Vitae consists of.

In this way, it would also explain why blood created with magic and powers is inert.
Probably the vitae sacrificed for cruac rites is turned into this kind of "soulless" blood in the aftermath

[Isator Levi]

I'd say no because both Kindred and Strix drain Vitae that is interchangible for all purposes where its medium isn't relevant (i.e. non-blood Vitae can't be spillt; this logistical difficulty is shared with ghouls who have blood Vitae but no means of spilling it themselves).

I would view the limits of Strix Vitae in Crúac as an indicator of ways in which they are not interchangeable; that if there's a difference based on how they can exit the corpus, there can also be a difference based in how it enters. The lack of a soul fails to produce the particular kind of vital breath that the Strix convert into Vitae, but the gratifying sensation of warm blood straight from the vein suffusing the undead tissues is a converter for the vampire.

I would see this as a dichotomy that reflects their distinct natures; the Strix is a more insubstantial being and feeds through a more ephemeral medium, while the Kindred are distinctly, viscerally physical, and the physical is what their Beast engages with. I'd see that in the references to the physical sensations and motions underlying a lot of what vampires do supernaturally, as well as how the Strix that embodies itself in something physical switches over to the physical diet.

[Satchel]

I would view the limits of Strix Vitae in Crúac as an indicator of ways in which they are not interchangeable; that if there's a difference based on how they can exit the corpus, there can also be a difference based in how it enters. The lack of a soul fails to produce the particular kind of vital breath that the Strix convert into Vitae, but the gratifying sensation of warm blood straight from the vein suffusing the undead tissues is a converter for the vampire.

I would see this as a dichotomy that reflects their distinct natures; the Strix is a more insubstantial being and feeds through a more ephemeral medium, while the Kindred are distinctly, viscerally physical, and the physical is what their Beast engages with. I'd see that in the references to the physical sensations and motions underlying a lot of what vampires do supernaturally, as well as how the Strix that embodies itself in something physical switches over to the physical diet.

Also worth pointing out: Within the text of Vampire, the Strix are the only source of the Soulless Condition, and through a power that lets them create Vitae-generating phylacteries, at that.

"Soulless victims produce no Vitae" is firmly contained within the sidebar on the Breath Drinking move, rather than in the sidebar on the Feed move or in the text of the Soulless Condition (which, despite the only source of the Condition in the book being restricted to living mortal targets, does have altered text relevant to Vampire), and Unnatural Affinity outright names several things that don't have souls as viable subjects whose only complication is managing to feed on them.

Stored blood and animal blood are thinner fare and hard to stomach at higher Blood Potency, but they are technically always viable sources of Vitae for Kindred, and the Strix reject Humanity and outright don't have feeding restrictions otherwise and hail from stranger spheres than vampires of mortal stock, so there's pretty strong odds for Blood-based Vitae being able to cobble together a semblance of a mortal-adjacent soul through the Embrace being an extension of a generally more worldly-connected medium for vital essence compared to the soul-harvesting smoke-monsters that give rise to the undead.