Talia al Ghul (Nolanverse)

Miranda Tate aka Talia al Ghul is the true main antagonist of the third and final Dark Knight trilogy movie, The Dark Knight Rises. She is the master of the League of Shadows and Bane's partner.

Before Talia was born, her mother, Ra's al Ghul's lover, was placed into a well converted into a prison known as The Pit while pregnant with her as punishment for having the child out of wedlock. After her mother was killed, Talia was befriended and protected by Bane, one of the most feared inmates of the Pit. Bane helped Taila escape at the cost of severely injuring himself. She later returned with her father to rescue her friend. However, Ra's quickly dropped Bane from the League of Shadows. For this action, Talia hated her father but was willing to inherit his plan of wiping out Gotham City.

She revealed this information as she literally backstabbed Bruce Wayne in his Batsuit about to take down her former protector, who was lying there after Batman turned his jaw injury on Bane in their rematch. Talia then takes the reactor core that Bane had placed in the Gotham Arena in the hopes of detonating it. Talia later dies when Selina Kyle and Commissioner Gordon both ram the truck carrying both her and the increasingly unstable reactor core off the top of a ramp.Even moments before her death when the heroes discover her in the wreckage, she asserts that she won, as the unstable nuclear reactor was only minutes from detonating in an Atomic explosion, forcing Batman to pilot the improvised Nuke out of Gotham using his high tech stealth plane so he would die saving the city.

Trivia

 * Marion Cotillard who played Taila is also started as Mal in Inception which directed by Christopher Nolan