Johnnathaniel Gabriel "John" Duncan is one of the twin children of Bree and Kaz Duncan. He and Natalie are fraternal, and he is younger than her by a minute. He has super speed and other bionics. John has a Bree-like personality-save a significant lack on intellect- even though he looks just like Kaz. He is 14 years old. He has a crush on Marie. He shares a name with his third cousin, John Duncan. In the future, he and Marie will marry and have 12 kids including Leana Duncan, Paul Duncan and Annie Duncan. They tried getting engaged once already, but were too young. He is called John G.