Rex is a descendant of both the original masters of earth and fire, and this, causes him to have a cross between the two elements, Magma. He was found one day as a child floating in a stream of lava coming off a volcano near Ignacia, he grew up in the town, with no definitive parents, and eventually became a builder before being recruited by Sensei Lloyd to become a ninja. Having heard similar tales from a blacksmith who owned a place called Four Weapons, he couldn't refuse. He joined the quest to defeat TALOW and bring down its head alongside Scott, John, and Nate. His weapon of choice is a hammer, and he's rarely seen without a smile on his face.