Equinox
Terry Sorenson was the son of two research scientists, his brilliant mother and struggling, unstable father. One night, his father's research exploded and killed him, but exposed Terry to mutagenic energy that left him shifting between a fiery and icy forms. Terry's mom tried unsuccessfully to cure him, but Terry's mutations grew stronger, and his mental state grew increasingly unstable.
Frustrated and irrational, Terry turned to crime to support his mom's research, encountering Iceman and the Human Torch. A later encounter with Spider-Man, Yellowjacket and the Wasp led towards the heroes helping Terry's mom in stabilizing his condition.
