Book 7 of Ayaka's Dog

(Demon Slayer, Bianbai, four female protagonists, decisive in killing, ruling the island country, both good and evil) Travel through Demon Slayer: Kimetsu no Yaiba and transform into the Thunderbolt General - Shadow. The purple thunder at the beginning saved the desperate Butterfly Kanae and Butterfly Ninja from the evil ghost's mouth. The system is unbound, leaving only the task of "killing Muzan Demonbutsuji"? It doesn't matter, the Naginus blade in her hand is enough to cut through all the filth in the world. "From now on, we are family." As a superior god, she clumsily learned to protect two young butterflies in troubled times. Teach them sword skills, reshape their breathing methods, and train them to become the sharpest blades. Just... "Sister Ying, the kitchen is forbidden!" This is the story of an invincible thunder god who takes care of children and kills ghosts in the world of demon slayers.