Which prophet told Hazael he would become king of Aram?

Answer: Elisha

Elisha wept before Hazael and said, 'The LORD has shown me that you will be king over Aram.'

““Why is my lord weeping?” asked Hazael. “Because I know the evil you will do to the Israelites,” Elisha replied. “You will set fire to their fortresses, kill their young men with the sword, dash their little ones to pieces, and rip open their pregnant women.””— 2 Kings 8:12 (BSB)