Once a carefree surfer whose only worry was catching the perfect wave, Ken Mack's body has been transformed into living Iridium, making him the reluctant hero known as Mettle.
Possibly the most inexperienced of the new trainees at Avengers Academy, due to the fact he is easily startled and frustrated during maneuvers, Mettle appeared to be well aware of his powers and how dangerous they can be to others if not properly honed. He soon discovered his observations of himself and the rest of the group he'd been partnered with were reaffirmed by some of the instructors, Henry Pym and Speedball to name two. Mettle was told he was among the most promising new recruits to join the academy, but in actuality, there was a concern he may stray from the righteous path due to some of the tortures inflicted upon him by Norman Osborn. Mettle got the chance to confront Osborn during a visit to the Raft penitentiary, but a prison riot didn't allow the time to get the answers he wanted, although Osborn gave Mettle hope that his condition could one-day be reversed.
Mettle got the chance to see himself in a possible future timeline when Korvac returned to take control of reality and force his ex-wife, Carina Walters, to love him again. Carina pulled an adult version of Mettle back through time, inserting Mettle's younger mind within. Once at his full potential, Mettle saw he was no closer to living the normal life he desired in the future than he was in the present. He attacked Korvac and refused to give in even when threatened with death because he admitted he did not want to live the rest of his days trapped inside his mutated body. Mettle did not die that day, and he was restored to his youthful form after Korvac's defeat, but he found solace in Hazmat, another student who shared an unwanted fate.