Hannibal

This telepathic alien came to National City to collect on a bounty issued on Kara for 300 Quartz Crowns. He took position outside Kara's apartment building and used his power to take control of Mon-El's body and had him fight against Kara and later Guardian. He was discovered by Winn and bluffed into stopping his control of him and then locked in the D.E.O. There, J'onn used his telepathic ability to look into his mind where he painfully revealed that the bounty was issued by Queen Rhea.