Concave and Convex World: Orphans of the Underworld

Foreword  According to legend, there is a race in the concave and convex world that never existed. Their history was erased, their souls were not allowed, and their achievements were not praised. They violated the rules of this world, thus angered the gods, and were given endless wails and pain. Thousands of lights, only one remains. I will hide your name and deprive you of your sins. Please face your past, present and future with a new look.  "My child, open your eyes and see this world, even though it is already devastated." "Isaya, forget it, remember it. Carve it into the coffin called time, and then go find your journey." Note: The two female protagonists in this book are friends and can fight each other. There are many private facilities. There will be some OOC in the character design, please protect yourself from lightning.