Ken Mack is a member of the Young Allies.
One day while Ken was surfing, another surfer crashed into him, ramming Ken's face with his surf board. Instead of killing him, the impact trauma accelerated a transformation already taking place under his skin. His skin peeled off, revealing a red iridium skull beneath. At the time of the accident, Ken was unaware of the transformation because the iridium has no nerve endings.
Mettle is brought onto the new incarnation of the Young Allies by the American Panther and Rescue. When the earth is fused with Counter-Earth he along with the other Allies fight Araña and the yet to be named New Slingers. He fights Avispa who takes his sister's place fighting Hazmat, leaving Mettle to face Estrella.
Fight For Your FreedomEdit
In a brutal fight with Singularity he is used almost like a wrecking ball where he would cause a building in Spanish Harlem to collapse. This building was the home of Victor Alvarez. After the terrible events he is taken captive by Singularity and handed over to the World Party.