Mirror Mantis is a new character introduced in Metal Slug Attack.
Mantis appears to be a young girl who is a renowned assassin rumored to have a 100% assassination rate, but she is most likely a newcomer in the industry. She dislikes failure, as she wants to maintain a good reputation.
She is works for a mysterious corporation to deal with spies and traitors; as this corporation is briefly mentioned in Maya's introduction and in-game description, it is likely that she works in the same corporation as her and Kelly.
In battle, she carries a backpack equipped with the latest in military technology, such as metal claws to climb ceilings, mantis-like blades (hence her name) and a temporarily cloaking device. If her mission ends in failure, she flees from the scene with the backpack's fold-in wings.
First appearing in "United Front the 31st", Mantis is tasked by the corporation to kill Allen O'Neil, which she accepts. Despite being an assassin, Mantis wipes out several groups of Rebel personnel protecting Allen to reach him. She tries to land a killing blow, but her blades are ineffective against Allen's muscles. Despite the obvious failure, Mantis tries to continue fighting, only to be reminded by Beatriz that she has no chance of doing so and suggests that she leave. Seeing no other choice, Mantis reluctantly complies and leaves the scene, aware that her reputation will tank for failing another mission.