Carrying a Knife but Not an Umbrella on a Rainy Night

Whenever it rains black at night, monsters will appear in the rain. They will attack humans and eat them. These monsters have very powerful attack power and are so numerous that humans cannot compete with them. Until a group of special people appear. Bathed in the black rain, they can gain power that rivals monsters, and protect the weak with the sharp blades in their hands. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.