Debby the Corsifa Is Emulous (Pre-Serialization)

In the deep depths of Hell lives a bloodthirsty demon known as "Debby the Corsifa." She loves a good fight, but not a single entity in Hell can match her in combat. Bored, she decides to blow off steam by wiping out the human race! However, after arriving on Earth, Debby meets an equally bored human named Rokurou Sugo just as he audibly wishes for someone to play games with.