Why did atilla kill his brother bleda?

Answer 1

he wanted all the power to himself

Answer 2

Attila and his brother Bleda co-ruled the Huns, however, Attila had him assassinated in order to consolidate his own power and become the sole ruler. Attila believed that Bleda was becoming a hindrance to his ambitions and saw him as a threat to his authority. Thus, he decided to eliminate his brother to secure his own position as the supreme leader of the Huns.