In the RV, the great bhArgava, ushanas kAvya, is a votary of the deva-s. In the itihAsa & purANa he becomes an enemy of the gods & partisan of the asura-s. In the Iranian tradition, he is interestingly a great hero-figure with daiva affinities. The baudhAyana-shrauta-sUtra 18.46-47 & jaiminIya brAhmaNa 1.154 onwards which belong to the late vaidika tradition give an intermediate picture.
There, bR^ihaspati & kAvya have respectively become the purohita-s of the deva-s & asura-s. What ever rite the deva-s did the asura-s did the same in a reverse format: this we believe is an old memory of the emergence of the counter-religion among the Iranians with its normative inversion.+++(4)+++ Thus, they had reached a stalemate. indra was aware that a 3-headed gandharva, suryavarchas, who lived in the middle of the ocean with his wife on a golden ship has the capacity to prognosticate the basis for victory in the conflict. Hence, indra went to the wife of the sUryavarchas & talked her into asking her husband about his prognosis. indra becoming a ray of light overheard them.
The gandharva said that bR^ihaspati & kAvya are equal as purohita-s. However, if both were on one side then the war would tilt in the favor of that side. indra having heard this became a green parrot & flew into the realm of the asura-s. There he lured the 4 wish-granting cows of virochana the prahlAdIya & with that lured shukra over the daiva side. The asura-s followed in hot pursuit to recover him & their cows. However, indra erected a skambha to suvarga-loka & that blocked the path of the asura-s even as he & shukra ascended to it. With that victory was that of the deva-s.
shukra was granted the immortal loka of the gandharva: this is likely an astronomical allegory for the inner near-solar orbit of Venus.+++(5)+++
In the baudhAyana text it is a mountain at kurukShetra where the kAvya was consigned. There is a clear Iranian parallel of the ascent of their cognate of the kAvya to the immortal realm on the vehicle powered by the daeva-s. The gandharva in the midst of the ocean provides a clear parallel to the Iranian gandareva, the guardian of the haoma, in the middle of the ocean.+++(4)+++ He is slain by the gadhA-wielding hero keresAspa after a fierce battle in course of which the gandareva kills several of keresAspa-s horses & also kidnaps his wife. The 3-headed sUryavarchas provides a connection to the Iranic gandareva in the sea by transferring the feature of trishiras tvAShTra to him.
jaiminIya holds that the men & the manes are on the side of the deva-s against the asura & their partisans, the rakShas-es & pishAcha-s. gandharva-s were neutral but once the deva-s beat the asura confederation, they claimed they were mentally on the daiva side & wanted a loka.+++(5)+++