Butterfly and Valkyrie

A butterfly flaps its wings, blowing a modern soul into a troubled world where demons and ghosts are resurrected and humanity is declining. Thirty years ago in this world, a plague broke out, and the mountain spirits and wild monsters were infected and turned into demons. Some are hidden between the virtual and the real, secretive and fierce, choosing people to devour; some are rising above the clouds and mists, moving stars to change battles, and twisting the universe.