Sixtrain is one of the many Autobot six-combiners who battle the evil forces of Scrash on Earth, such as Battle Gaia. He is the older brother of Sixliner, who he is very similar to. In an alternate timeline/universe, Sixtrain has blended into human society along with the other Micromasters, and fights against the evil Decepticon Micromasters when they threaten cities. In either case, he is composed of Atlan, Converter, Desire, Rays, San D-Go and Windy.