Halcyon was a deaf mutant with the power to retain a steady heartbeat. A math major at Columbia University, he was also a skilled street racer, whose power allowed him to have a characteristic breezy demeanor. When Tony Stark wanted to test his new 1978 Dodge Aspen, he approached the car meet frequented by Halcyon at Amsterdam Avenue to bet five thousand dollars. They made him race Halcyon, who beat Tony sharply. Tony would then regularly race Halcyon but never managed to beat him.
Following the return of the hyper-intelligent cyborg Korvac, Stark decided to seek help from allies who would not be in the villain's radar. Together with Patsy Walker, Tony enlisted Halcyon's help in finding these people.
Powers and Abilities
Superhuman Cardiology: Halcyon's mutant super power affects his heart in a way that his heart rate never goes over 70 bpm, making him unflinching.