During the events of Inhumanity and Infinity, when the king of the Inhumans, Blackagar Boltagon, released the Terrigen Mists on the world, Mark was transformed into an Inhuman. Unlike many others, his body did not reject the Terrigenesis, and he acquired a slightly new appearance (the horn protruding from his forehead) and new powers.
When the High Evolutionary sent his Revolutionaries to wipe out genetic aberrations on Earth, Mark was targeted, and nearly killed, but he was aided by Sun Girl. These aberrations included Inhumans, mutants, Atlanteans, those who had been 'corrupted' by magic, and those whose molecular structure had been altered by scientific experimentation and/or accidents. This conflict put Mark in direct contact with the newly formed New Warriors. Each of them is targeted by the Evolutionaries for a different reason. The group leader, Vance Astrovik (aka Justice) is targeted for being a mutant. Robbie Baldwin (aka Speedball) is targeted for the molecular alterations in his system. Faira Sar Namora (aka Water Snake) is an Atlantean. Aracely Penalba (aka Hummingbird) has mystical origins. And Sun Girl, though human, is targeted for helping the others. This new incarnation of the New Warriors battled the High Evolutionary, and defeated him, proceeding to take on new future challenges.
As an Inhuman, Mark has the ability absorb all kinds of energy by sucking it into his mouth, making it appear as if he "eats" the energy. This fuels his enhanced strength, stamina, speed, and endurance. Mark can also transform into a large quadrupedal dragon-like creature with a resemblance similar to that of the Haechi, hence the codename. In this form, Mark retains his wits and his ability to "eat" energy. He can also redirect this energy, through his mouth.