The Inevitable Ending.

Weekly Days Chapter Uploads. This series takes place in a world where an alternate dimension—Hell—exists. Demons can crawl through cracks in the dimensional barrier, though only the weaker ones make it through. But even these "small fry" demons are deadly to humans. Their arrival forced humanity to adapt, awakening elemental powers in people and giving rise to the Anti-Devil Corporation (ADC). The ADC is split into 7 ranks: Ember (F), Smoulder (E), Ignite (D), Kindlewing (C), Firecrest (B), Ashborne (A), and Solstice (S)—the highest class, made up of only 12 elite demon slayers. The power system is called Nyth—a type of soul-energy. Every person is born with a Seedling Nyth Core, unstable and weak. With intense training, they can evolve through stages, rest of the things are in the novel.