text: The relationship between ahuras / asuras and daevas / devas in Indo-Aryan times, was discussed at length by F.B.J. Kuiper. This theory and other Avesta-related hypotheses developed over the 20th century, are all now questioned particularly for lack of archaeological evidence. Asko Parpola has re-opened this debate by presenting archaeological and linguistic evidence, but notes that the links may go earlier to Uralic languages roots. The Indo-Aryan Asura may also be related to the Assyrian deity Ashur.
  Relation to Germanic deities
  Some scholars such as Asko Parpola suggest that the word Asura may be related to proto-Uralic and proto-Germanic history. The Aesir-Asura correspondence is the relation between Vedic Sanskrit Asura and Old Norse Æsir and Proto-Uralic *asera, all of which mean 'lord, powerful spirit, god'. Parpola states that the correspondence extends beyond Asera-Asura, and extends to a host of parallels such as Inmar-Indra, Sampas-Stambha and many other elements of respective mythologies.
  Characteristics
  In the earliest Vedic literature, all supernatural beings are called Devas and Asuras. A much-studied hymn of the Rig Veda states Devav asura (Asuras who have become Devas), and contrasts it with Asura adevah (Asuras who are not Devas). Each Asura and Deva emerges from the same father (Prajapati), share the same residence (Loka), eat together the same food and drinks (Soma), and have innate potential, knowledge and special powers in Hindu mythology; the only thing that distinguishes "Asura who become Deva" from "Asura who remain Asura" is intent, action and choices they make in their mythic lives.