Lord of the Flies

Concept: “The lord of flies appears whenever the smell of death is too strong for any human to endure, when rivers of blood flow and soak the earth.”
Content: A giant, gross fly commanding a bunch of regular-size, gross flies
Writing: Concise but effective in the flavor text and mechanics
Art/design: A strange but oddly endearing illustration
Usability: High HP + ability to bypass armor and ignore manipulation = potentially lethal