He is primarily a thunder god who defeats the demons of drought and darkness and frees the waters or wings the light. He is also the god of battle, assisting the victorious Aryan in defeating his aboriginal foes.

His physical characteristics, such as his body and head, are frequently mentioned after he has drunk Soma; he agitates his jaws and beard; and his belly is frequently mentioned in connection with his great powers of drinking Soma. Being tawny (hári) in colour, he is also tawny-haired and tawny-bearded. His arms are frequently mentioned because they wield the thunderbolt (vájra), which is his exclusive weapon and represents the lightning strike in legend. Tvastr crafted this bolt for him, which was made of iron (ayasá), golden, tawny, sharp, and many-pointed, and was sometimes referred to as a stone or rock. Several vájra epithets, compounds, or derivatives, such as vájra-bahu with the bolt in his arm and vajrn wielder of the bolt, are almost always applied to him. He is sometimes described as being armed with a bow and arrows, as well as a hook (ankusá).

He is a car-fighter (rathesthá), with a golden car drawn by two tawny steeds (hári). The divine artificers, the Rbhus, created both his car and his steeds. Because Indra is more addicted to Soma than any of the other gods, he is known as the 'Soma-drinker' (Somapá). This beverage stimulates him to carry out his warlike deeds; for example, he is said to have drunk three lakes of Soma before slaughtering Vrtra. One entire hymn (x. 119) is a monologue in which Indra, drunk on Soma, boasts of his greatness and might.

Indra is frequently mentioned as having been born, and two entire hymns are dedicated to the subject. His father, like Agni's, appears to be Dyaus, but other passages imply that he is Tvastr, the artificer among the gods. Indra's twin brother is Agni, and Pusan (vi. 54) is also his brother. Indrani, his wife, is frequently mentioned. Indra is linked to a number of other deities. His main allies are the Maruts (i. 85), who constantly assist him in his conflicts. As a result, he is known by the epithet Martvant, which is accompanied by the Maruts. Agni is the god most frequently associated with him as a dual divinity. Indra is also frequently associated with Varuna (vii. 86) and Vayu, the god of the wind, and less frequently with Soma (viii. 48), Brhaspati (iv. 50), Pusan, and Visnu.

Because Indra is enormous in size, it is said that he would be equal to the earth even if it were ten times its current size. His greatness and power are constantly emphasised: neither gods nor men have reached the pinnacle of his power, and there is no one like him among the gods. Thus, he is known by many names, including sákrá and sácivant mighty, sácipáti lord of might, and satákratu having a hundred powers.

The fundamental myth underlying his nature is described with extreme frequency and variation. Exhilarated by Soma and usually accompanied by the Maruts, he attacks the chief demon of drought, Vrtra, but also the serpent (áhi). When the great battle begins, Heaven and Earth tremble. Vrtra, who encompasses the waters, is shattered by his bolt, earning him the exclusive moniker apsu-jit, or conqueror of the waters. As a result of the ongoing conflict, he pierces the mountain and frees the waters that have been imprisoned like imprisoned cows. The physical elements of conflict are almost always the bolt, the mountain, the waters or rivers, while lightning, thunder, cloud, and rain are rarely directly named. The waters are frequently terrestrial, but they are also frequently aerial and celestial.

The clouds are mountains (párvata, gir), on which the demons lie or dwell, or from which Indra castes them, or to which he cleaves in order to release the waters. Or the cloud is a rock (ádri) that encompasses and releases the cows (as the waters are sometimes called). Clouds appear as cows because they contain the waters; they are also known as udder (dhar), spring (tsa), cask (kávandha), and pail (kósa). Furthermore, the clouds appear as the aerial demons' fortresses (pras), described as moving, autumnal, made of iron or stone, and 90, 99, or 100 in number. Indra shatters them, earning him the moniker "fort-destroyer" (parbhd).

However, the chief and specific epithet of Indra is 'Vrtra-slayer' (Vrtra-hán), owing to the mythical importance of the battle with the demon. The Maruts are his regular allies in this fight, but Agni, Soma, and Visnu also frequently assist him. Indra also fights a slew of minor demons; he is sometimes described as annihilating demons in general, the Raksases or the Asuras.

The victory of light, sun, and dawn is linked to the release of the waters. Indra is thus summoned to slay Vrtra and win the light. He visible placed the sun in the heavens after slaying Vrtra and releasing the waters for man. When Indra blew the serpent out of the air, the sun shone brightly. There is frequently no mention of the Vrtra fight here. Indra is then simply said to have discovered the light; he gained the sun or discovered it in the darkness and created a path for it. He creates both the dawn and the sun, and he opens the darkness with the dawn and the sun. The cattle. The morning beams, which are elsewhere compared to cattle emerging from their dark stalls, are most likely mentioned alongside the sun and dawn, or with the sun alone, as found, released, or won by Indra.

When the dawns went to meet Indra, he became the lord of the cows; when he defeated Vrtra, he made the cows of the nights visible. The restoration of the sun after the darkness of the thunderstorm appears to be confused with the recovery of the sun from the darkness of night at dawn. The latter feature is most likely a continuation of the former. Indra's connection with the thunderstorm is devoid of mythological imagery in a few passages, such as when he is said to have created the lightnings of heaven and directed the action of the waters downwards. The gaining of Soma is linked to the Vrtra-fight, the winning of the cows and the sun. Thus, when Indra drove the serpent from the air, fires, the sun, and Soma shone forth; he won Soma at the same time as the cows.

Indra is frequently credited with great cosmic feats. He calmed the trembling mountains and plains. He stretches out heaven and earth like a hide; he separates heaven and earth like two wheels are separated by the axle; he transformed the non-existent into the existent in an instant. Indra's victory over a demon who held heaven and earth together is sometimes described as the separation and support of heaven and earth.

Warriors constantly invoke Indra as the destroyer of demons in combat. As the great god of battle, he is summoned more frequently than any other deity to aid the Aryans in their conflicts with earthly adversaries. He guards the Aryan colour while subjecting the black skin. He dispersed 50,000 black people. He subjected the Dasyus to the Aryan and gave the Aryan land. Indra is generally regarded as the protector, helper, and friend of his devotees. He is described as bestowing wealth on them as a result of their victories. His generosity is so distinctive that the frequent attribute maghávan bountiful is almost entirely his.

Aside from the central myth of the Vrtra-fight, Indra is linked to a number of minor stories. In several passages, he is described as shattering the car of Usas, goddess of dawn (iv. 51); this trait is most likely based on the idea of Indra bringing the sun when it is held back by the delaying dawn. He is also said to have stopped the Sun's steeds, causing the latter to lose a wheel of his car. Indra is also associated with the myth of Soma's victory, as the eagle brings the draught of immortality from the highest heaven to him. Another myth concerns Indra's capture, with the assistance of Sarama, of cows imprisoned in a cave by demons known as Panis.

Various stories are told of Indra fighting for individual protégés, such as King Sudas, against terrestrial foes, despite the fact that they are mixed with theological elements. Indra's characteristics are primarily those of physical superiority and dominion over the physical world. He is an irresistible fighter, an inexhaustible lavisher of the highest goods on mankind, but he is also sensual and immoral in various ways, such as excessive eating and drinking, and cruelty in killing his own father Tvastr. He stands in stark contrast to Varuna, the RV's other great universal monarch, who wields passive and peaceful sway, applies natural laws consistently, upholds moral order, and possesses lofty ethical characteristics.

The name Indra is pre-Indian, as it appears in the Avesta as that of a demon; the term verethraghna (=Vrtrahán) appears there as the designation of the God of Victory, though it is unrelated to Indra. Thus, it appears likely that a god resembling the RV's Vrtra-slaying Indra existed during the Indo-Iranian period. The word's etymology is unknown, but its radical portion ind may be related to that in ind-u drop.