Same as Enlil, Indra originally was the supreme ruler of the gods. He was the leader of the Devas, the god of war, the god of thunder and storms, the greatest of all warriors, the strongest of all beings. He was the defender of gods and mankind against the forces of evil.
Indra is described as being very powerful, with a reddish complexion, and with either two or four very long arms. His parents were the sky god Dyaus Pita (Enlil) and the earth goddess Prthivi (Ki). He was given numerous titles including Sakra ("Powerful"), Vajri ("the Thunderer"), Purandara ("Destroyer of Cities"), Meghavahana ("Rider of the Clouds"), and Svargapati ("the Lord of Heaven (air)").
Like Zeus,
Indra was the god of thunder, wielding the celestial weapon Vajra, the
lightening bolt. He also had the power to revive slain warriors who had
fallen in battle. Indra held court at Svarga, his heaven in the clouds
surrounding the highest peak of the sacred mountain Meru. (Zeus held court
on mount Olympus.)
Same as Odin, who hosted his slain North men warriors in Valhalla, there was an enormous hall in Svarga, when warriors went after being killed in battle. Indra and the beautiful Indrani presided over their version of paradise.
In Brahmanic and later times, Indra slowly lost much of his grandeur. He was supplanted by Shiva as most important god. Indra eventually was given the role of weather god and lord of the lesser gods.
All these just seem to be different names for the same god, namely the lord of the powers of the air spoken of by Paul.
To you did he give life, when you were dead through your wrongdoing and sins in which you were living in the past, after the ways of this present world, doing the pleasure of the lord of the power of the air, the spirit who is now working in those who go against the purpose of God. Eph 2:2