Shortly after "Nocturne"s release, a duology titled ' ("Digital Devil Saga: Avatar Tuner" in Japan) was created based around similar systems to "Nocturne", and was also intended as a more accessible gaming experience. Two tactical role-playing games have been developed by Atlus for the DS under the "Devil Survivor" moniker: the original and '. Both have received expanded ports for the 3DS. Other subseries include ', a series aimed at a younger audience and using a pure fantasy setting; ', which was inspired by the popular "Pokémon" series; and "Majin Tensei", a series of strategy games. Two notable stand-alone spin-offs are action spin-off "Jack Bros." and "Tokyo Mirage Sessions ♯FE", a crossover with Intelligent Systems' "Fire Emblem" series.