Maenad

Maenas (マイナス, Mainasu) is a villain in Final Fantasy IV the After: Tsuki no Kikan. During most the game her true identity is unknown, and she goes by the name of Mysterious Maiden (謎の少女, Nazo no Shojō). She resembles the Summoner Rydia and shares her power to summon Eidolons. Her power as of yet seems unmatched, and she has yet to be defeated in even one of the many battles she has fought in. She can also use the powers of mind control to great effect. The evil side of Kain Highwind joins her in her mission in exchange for a chance to kill Cecil. It is ultimately revealed that Maenas was but one of many mass-produced beings designed to capture all eight Crystals for the Creator.

Story
Maenas first appears on the Red Moon where she is able to defeat both Golbez and Fusoya and destroy the Crystal Palace. She then goes down to Earth and attacks Baron, defeating the Red Wings with a swarm of monsters. Using the power of Bahamut, Maenas is able to beat King Cecil of Baron. Moving into the Feymarch, Maenas turns the entire Eidolon populace to stone, leaving Rydia unable to use her Summoner powers. Moving throughout the world, she is able to gather all eight Crystals, but also unifies the forces of good against her. They travel to the Moon to fight her. When the party finally encounters her here, she summons Bahamut, who later pushes her back after coming to his senses. It is soon discovered that Maenas is just one of many mass-produced beings, which continue to antagonize the group as they work their way toward The Creator, the true mastermind of all that has happened. Maenas later appears to battle The Creator as well, and appears to destroy herself and the being with a Meteor spell.

In the aftermath, one of the mass-produced Maenases, only a child, is taken in by Rydia and named Cuore (クオレ, Kuore).