A different world called "Grey Mist City" that combines the Victorian style with mysterious elements of Cthulhu. This is the habitat of various supernatural creatures, monsters, demons, angels and other beings. Humans here are a rare race that is weak, enslaved or used as material. The city is ruled by a loose council of monsters and is filled with dangers and opportunities. The power system is divided into three branches: "old days", "potion" and "contract", among which "potion" is the lowest threshold to transcendence.