Steppens D. Storm is a 33-year-old scientist and also an assassin who comes from the Town of St. Eden in South Blue, along with his twin sister, Steppens D. Ellie. He owns an extremely rare, special ability that can spawn and control the movements of the atoms, beside the three types of Haki, since he and his sister had lost his father and older brothers in an assault by the Marines and a few government officers 27 years ago.