I thank sirs Sangom, KRS and Raghy for their replies. Raghy sir's post on Ahura Mazda got me to write this (because a lot of people assume asuras was always persian or did not become indian). This is going to be long (will be breaking into parts), please bear with me. Some of the vedic mantras may not have dialectic marks, forgive me. This may also help understand some historical transformations, and thus, various contexts of karma and maya, interpreted by various texts.
The Ahura Mazda is no doubt the Asura Mazda or wise lord of the Zoroastrians. However, the epithet asura (used to denote the asuras) was used for Devas also within the vedic texts. I present the specific cases of the asuras, Rudra and Varuna. Agni is also an asura and is praised as Varuna himself in Krishna Yajur Taittiriya Samhita 1.2.10; but Agni was seized and re-established by the Devas in the Taittiriya Samhita Prapathaka 5. It denotes a struggle scenario leading to the antagonism between devas and asuras. Reasons for the antagonism can be found in the text itself. All the below verse are from the Krishna Yajur Taittiriya Samhita (TS) unless otherwise indicated.
In the early part of the TS, there is no antagonism against asuras. In fact they are praised as:
tvam agne rudro asuro maho divas tvam śardho mārutam pṛkṣa īśiṣe (TS 1.2.14.1) meaning, Thou, O Agni, art Rudra, the Asura of the mighty sky, Thou art the host of the Maruts, thou art lord of food…
Then the conflict happened in prapathaka 5 leading to the rekindling and reestablishment of fire. The whole prapathaka 5 is worth reading. For synopsis and for those who cannot go thru the text, am presenting some verses below:
devāsurāḥ saṃyattā āsan te devā vijayam upayanto 'gnau vāmaṃ vasu saṃ ny adadhata| idam u no bhavaiṣyati yadi no jesyantīti tad agnir ny akāmayata tenāpākrāmat tad devāvijityāvarurutsamānā anv āyan tad asya sahasāditsanta so 'rodid yad arodīt tad rudrasya rudratvam| yad aśrv aśīyata tat||
Meaning, The gods and the asuras were in conflict; the gods, in anticipation of the contest, deposited in agni their desirable riches (thinking),'This will still be ours, if they defeat us. Agni desired it and went away with it. The gods having defeated the asuras pursued Agni desirous of recovering it. They sought violently to take it from him. He wept; in that he wept (arodit), that is why Rudra has his name. The tear that was shed became silver; therefore silver is not a suitable gift, for it is born of tears.
Thereafter TS 1.5.7.6 says there is a pipe with projections, by which Devas made piercings of hundreds of Asuras; in that he takes up the kindling-stick with this verse, the sacrificer hurls the hundred-slaying (verse) as a bolt against his enemy to lay (him) low without fail. Since agni now belongs to the devas, they have the samidham (kindling-stick) which they use against the asuras.
War between Devas and Asuras continue in the TS 1.5.9 which says:
ahar devānām āsīd rātrir asurāņām te sura yad devanaṃ vittaṃ vedyam āsīt tena saha || rātrim prāviśan te devā hīnā amanyanta te 'paśyan| āgneyī rātrir āgneyāḥ paśava imam evāgnim stavāma sa na stutaḥ paśun punar dāsyatīti te 'gnim astuvant sa ebhya stuto rātriyā adhy ahar abhi paśūn nir ārjat te devāḥ paśun vittvā kāmām akurvata ya evaṃ vidvān agnim upatiṣṭhate paśumān bhavati||
Meaning, The day was the gods', the night the Asuras'. The Asuras entered night with all the precious wealth of the gods; the gods thought that they were abandoned; they perceived, 'The night is Agni's, cattle are Agni's; verily let us praise Agni here; he being praised by us will restore our cattle).
The fight for agni is closely linked to the fight for cattle. In Prapathaka 5, there is reestablishing of Agni (punarAdheyam). Since Pusan and Tvastr established it, so the cattle are said to be Pusan’s and Tvastra’s. Manu also established it so the offspring are those of Manu. However, Agni after being established desires a share, and so assailed the offspring and cattle of the sacrifice. On doing so, the verse says, “having removed ‘it’ one should re-establish ‘it’, unite with his own potion and is (thus) verily appeased”.
From the above, as one can note, having defeated the asuras, the devas now have agni (the right to agni), the samidham (kindling-stick) and the cattle. It is obvious the fight for Agni pertains also to cattle because cattle are sacrificed to Devas. This point (of animal slaughter) may be compared against Zoroastrian belief, where Ahura Mazda (the asura) tells Zarathustra to protect the cow. Possibly this indicates, the Asuras were defeated and the Devas now have the cattle and the right to sacrifice them. Possibly, cow protection continued amongst those who opposed the so-called brahmanical sacrifices.
In the first verse of the TS itself, Rudra’s dart is sought to be avoided and there is a proclamation to abide with the lord of the cattle and protect the cattle of the sacrifice. The verse says the vedi’s sacrificial straw was made by Manu fashioned with the Svadha call. Since in the subsequent verses we find Manu restablished agni for devas it is apparent Manu, Pusan, Tvastra were companions with Indra as the slayer of the brahman Vrtra. The Yajur is said to belong to the Kshatriyas, but we see the brahman being established at the beginning of the sacrifice.
After this fight (between devas and asuras), Agni is addressed as Asura (just once) in verse 1.6.6.4. The fight between devas and asura is continued in verse 1.6.10:
yajñasya vai samrddhena devah suvargam lokam ayan yajñasya vyrddhenasuran para bhavayan yan me agne asya yajñasya risyad ity aha yajñasyaiva tat samrdhhena yajamanah suvargam lokam eti yajñasya vyrddhena bhratrvyan para bhavayati| agnihotram etabhir vyahrtibhir upa sadayed yajñamukham va agnihotram brahmaita vyahrtayo yajñamukha eva brahma||
Meaning, With the prosperous part of the sacrifice the gods went to the world of heaven, with the unsuccessful part they overcame the Asuras. 'Whatever, O Agni, in this sacrifice of mine may be spoiled', he says; verily with the prosperous part of the sacrifice the sacrificer goes to the world of heaven, with the unsuccessful part he overcomes the foes. With these Vyahrtis he should set down the Agnihotra. The Agnihotra is the beginning of the sacrifice, these Vyahrtis are the Brahman; verily at the beginning of the sacrifice he makes the Brahman.
Whether Manu, one of those who reestablished Agni for the Devas is the same Manu of Manusmriti, it is not possible to say. But in Manusmriti (or in other dharmashastras in general), various forms of meat including cow meat hallowed by mantras is fit for consumption of dvijas and brahmans. There are a number of verses in the Krishna Yajur Taittariya Samhita itself which prescribe slaughter of various types of cattle to the devas. IMO, although popular belief credits ahimsa for animals to Buddhism and Jainism, the credit should go to the first teacher in all known literature who gave the message, ie, to Ahura Mazda. It is an other matter that Zoroastrians today eat all kinds of meat while Brahmans who perform brahmanical sacrifices are largely vegetarian
To be contd..