Balasar became suspicious of Nala the Platinum Cadre's cleric and decided to infiltrate the order. He was initiated into the order's rites although he didn't fully open himself up to Bahamut's power (which was actually Tiamat's power). Balasar found Nala's secret apartments in the catacombs beneath Djerad Thymar. There he found papers that proved conclusively that she was a priestess of Tiamat. Balasar's accusations led to a duel between Medrash and the Platimum Cadre's leader that Medrash won. Nala then fled to the Ash giant citadel (Ashhold) in the Black Ash Plain. Balasar killed Nala during the final battle between the Tymantherans and the Ash giants.
Like most dragonborn, Balasar doesn't follow the teachings of any diety.