A thin, ghostly, and cheerful assassin hailing from the city of Monaco and going by the same name. Monaco is directed by the unconscious will of the people of her city state, 'erasing' those the public wishes would disappear. Her strength and speed both increase dramatically in response to the will of the people. The more the inhabitants wish for something to happen, the stronger, faster, and more compelled she becomes to make it a reality.

After appearing in response to the voices of the people in their darkest hour, Monaco is heralded as a hero by the city state. However, her actions are controlled by their unconscious will, and the city's new dark messiah is only as good as those that direct her.

Her pension for swiftly beheading her victims with high speed kicks earned her the nickname 'Guillotine' among the inhabitants of Monaco.