Alfa X is a fictional character in Shinkansen Henkei Robo Shinkalion, appearing as one of the Shinkalion units rather than a human cast member. It is a special, high-performance Shinkalion associated with the Alfa-X train, designed with advanced capabilities and a sleek, futuristic appearance. In the series, Alfa X serves as a powerful ally in battles against threats to the rail network, representing cutting-edge technology and the next evolution of Shinkalion development.