The Oath of the Vayuputras: The Shiva Trilogy Book 3

Today, Shiva is a god. But four thousand years ago, he was just a man - until he brought his people to Meluha, a near-perfect empire founded by the great king Lord Ram. There he discovered he was the Neelkanth, a barbarian long prophesied to be Meluha's saviour.
But in his hour of victory fighting the Chandravanshis - Meluha's enemy - he discovered they had their own prophecy.
Now he must fight to uncover the treachery within his inner circle, and unmask those who are about to destroy all that he has fought for. Shiva is about to learn that good and evil are two sides of the same coin...