There’s a few comparative mythographic ideas out there that are simple, intuitive, comfortable, persistent … and downright wrong.
One of these is the thorny thicket of presumptions which have grown up around three not-unrelated sets of terminology from the Vedic, Eddic, and Zoroastrian corpuses. The core of which is basically that as there was an Aesir-Vanir War in the Norse accounting, as there is a long-running war against the A’Sura waged by the Devas in Hinduism, and as the Zoroastrians have a conflict between ‘Ahura’ and ‘Daeva’ …
… that this therefore implies that not only are all of these conflicts basically thematically coterminous, but that they’re effectively waged between the same groups, with closely familiar sounding names in each language and mythology.
It’s not hard to see how this perception has eventuated – like I said, it’s simple, intuitive, ‘comfortable’, and reduces a huge array of complex material down to one seriously simple point … with the added ‘lure’ that this would in theory allow for a ‘foundation’ anchor to further exploration of each of these corpuses upon the others’ terms.
There are also, importantly, a few strands of truth amidst this tapestry of lies – which therefore makes the whole thing hang together ever more frustratingly enduringly than might otherwise be the case.
Confused? We’ll start at the beginning. Or, at least, with the oldest material available to us.
The presumption brought to these earliest Hindu scriptural sources is that “Asura” and “Deva” refer to members of two different ‘tribal’ groups – in the manner of “Aesir” and “Vanir” in the Nordic corpus. While it *is* true that particularly in later usage, “A’Sura” and “Deva” are different, even fundamentally opposed classes … there is no sensible comparison to be made between “Asura-Deva” and “Aesir-Vanir”.
We can demonstrate this linguistically, and also via mythology.
Asura and Deva are words that do *not* intrinsically denote, in their RigVedic usage, different ‘tribes’ of beings. How do we know? Because both terms get applied to the same specific deities. For example, Rudra is referred to as an Asura … but also a Deva; and this is not entirely uncommon for an array of prominent Vedic deities, especially when it is noted that the Visvedeva collective noun most definitely *also* includes Asura deities within its number.
Now, this is not to attempt to ignore that in subsequent scripture, the meaning of “Asura” becomes more closely associated with … demons, but here’s the thing: the “Asura” that means “demon” is *not*, per native etymology on the subject, the same as the”Asura” referring to a ‘Sire’ [that’ll do for a stand-in of RigVedic ‘Asura’ in terms of meaning-field for now]. Rather, it is a *neologism* that is from a different root: “A’Sura”, meaning “Opposite to/Opposed To/Anti” [“A-“] “Shining” [“Sura” – same root iirc as “Surya”].
This becomes rather relevant when we consider what “Deva” means [partially] and is derived from – a term connoting ‘Shining One’, ‘Celestial’ [the radiant area of the cosmos being linked to this, and the related Dyaus (Pitar) terminology being from a closely aligned term for, effectively, the (Daylight) Sky], and the broader meaning-field attached to the solar regime in Vedic metaphysics, mythology, cosmology, etc.
That is to say, “A’Sura” is one who is insurrectionist against, opposed to, the Divine. And, funnily enough, who is often smited down upon with great vengeance and furious ugra, by particular Asura Divinities.
So: “Asura” and “Deva”, referring to the same deities, cannot mean ‘different tribes’ in the manner of “Aesir” and “Vanir” … because it’s not a case of “the group of this tribe incorporates some members of this other tribe” – it’s a case of *the same beings* being both, a lot of the time. Although not all Devas are referred to as Asura, and for other reasons, the terms have different shades of meaning in their application – different qualities being referred to.
Meanwhile, “A’Sura” and “Deva” *also* cannot mean ‘different tribes’ in the manner of “Aesir” and “Vanir” … because it’s not a case of a tribe of Gods choosing to adopt/incorporate these “Anti-Gods” [to translate “A’Sura” somewhat figuratively] into Their number. But rather, one of a significant and onrunning emnity, which appears to only *intensify and became far more broadly salient* with the passage of time. [There are some ‘accomodations’, as applies Rahu/Ketu, but I do not think that this matches up well with the Nordic approach for … a number of reasons; and also because despite Graha status, it is not that these are regarded as Gods].
Now, to bring things around to Nordic mythology, we again have a situtaion wherein “Asura” and “Deva” are *not* going to work out as “Aesir” and “Vanir”, and this we can demonstrate linguistically.
There is a well-known d=>t sound-shift [observable in, for instance, “Dent” and “Tooth”, “Dict” and “Teach”, etc etc. [I’m being a bit lazy with my examples there for simple illustrative effect, before somebody calls me out on that]]; so it should come as absolutely no surprise to find that “Tyr”, “Tiwaz”, appear to be etymologically related to “Deva”, “Deus”.
“Tyr”, despite being rather prominently thought of as a specific theonym for a specific Norse God, is *also* a general term in much the same manner as “Deva”, applied to several Nordic Deities – Odin has … quite a few theonyms [because of course He does] that directly incorporate a “-tyr” designator.
Why does this matter? Because earlier, I pointed out that Rudra is referred to as both “Asura” and “Deva” [and, indeed, in later Vedic and Puranic era texts, this leads to “MahaDeva” – The Great God] ; and as many are now increasingly aware, Odin Is Rudra. Hence, Odin being both Aesir and -tyr, is rather strongly comparable to what is going on with that earlier cited Hindu example.
But there is one more element that must be considered, in any discussion of “Asura” and “Deva”, and that is the ‘pandemonium’ phenomenon – aka the ‘fossilization’ of a certain effort to upend the prevailing Indo-Iranian [and broader Indo-European] religious orthodoxy , in the language used by those insurrectionists.
This explains why “Daeva” has come to mean “Demon” in those Persianate languages. Due to a rather direct effort to ‘demonize’ many of The Gods, in the course of the “reform” effort and as subsequent ‘culture jamming’ to ’embed’ this.
This is, in many ways, the *opposite* of the Aesir-Vanir dynamic. Insofar as it represents not only a *sundering* of an essential unity via the would-be ‘casting down’ and ‘casting out’ by mortal hand of some Gods from a group [a moment’s consideration shall reveal why this is, so to speak, *doubly* heretical] , but also of *setting into motion* a conflict rather than causing one to be resolved.
At various previous points, I have referenced Shiva-Odin-Rudra to illustrate the ambit and the application of terms. It should come as no surprise to find that the “reformers” referred to herein also sought to make use of their weaponized ‘daeva’ terminology against Him. And also against an array of other prominent Vedic deities such as Indra.
A situation which really does help to show just how/why various groupings of Indo-Iranians immediately proximate to all of this going on … did not take kindly to it, and made war against the insurgents. For some time afteward, the Persianate/Zoroastrian feeling toward the #GangSteppe peoples to the North in particular, was one of fear and hostility – which is also related, I rather strongly believe, to just what it is that Odin, and various Shaivite-relevant images , fundamentally is in some regards … a Spear and/or Bow armed Wind-Rider.
i) there is not a useful relationship between “Asura & Deva”, and “Aesir and Vanir”
ii) there is a useful relationship between “Asura & Deva” and “Aesir & -tyr”
iii) there is not a useful relationship between “Asura & Deva” and “A’Sura and Deva” [although due to the adjectival use of “Asura”, there are a literal handful of instances wherein one or two demon progenitors are referred to with such a title … from memory, it’s in at least one case basically that – “Sire”, as in, a patriarch of their brood, and a lord thereof]
iv) there is not a useful relationship between “A’Sura and Deva” and “Aesir and Vanir”
v) there IS a useful relationship between “Deva” and “Daeva” … insofar as it helps to show why the Zoroastrians are the odd man out [to speak more politely than is perhaps warranted], and particularly because it shows that several prominent “Aesir” [e.g. Odin, Thor] are regarded as being “Daeva” by them.