Supergirl

Supergirl (real name Kara In-Ze/Kent) is a member of the Justice League, the last Argoan, and Superman's foster cousin. She is also dating Kyle Rayner, Green Lantern.

Early adventures
Kara In-Ze was the only survivor from Krypton's sister planet, Argo. While exploring the sector of space once occupied by Krypton, Superman discovered a hidden cryogenic facility which had sustained heavy damage. Only one chamber was intact, containing the last survivor of Argo: Kara. Taking the young woman back to Earth, Superman introduced Kara to his adoptive parents. The Kents took her in under the guise of Jonathan Kent's teenaged niece.

Inspired by her "cousin" Clark, Kara made a costume similar to Superman's and joined him on a few missions as Supergirl. Kara frequently visited Clark in Metropolis and, as Supergirl, she had full access to Superman's Fortress of Solitude. In Supergirl, Superman found a living link to his alien heritage, and someone he could talk to about his dual lives as Superman and Clark Kent. She became a frequent friendly ally who could be trusted with Superman's secrets.

Before joining the Justice League, Kara had little interaction with other heroes. Her first official team-up was with Batgirl. When Livewire teamed up with Poison Ivy and Harley Quinn, Batman, asking for Superman's help, inadvertently gets Kara instead. Together Batgirl and Supergirl defeat the trio of super-villains, and form a close friendship. Evident by Kara's sadness when Barbara retired from being Batgirl, though the two continued to stay close friends.

Missions
Kara was living in Kansas for three years, under Clark's instructions, until she was finally recruited into the new Justice League where she was put under the joint tutelage of Shayera and John Stewart. Supergirl's juvenile and playful spirit charmed Green Arrow and the two became friends.

Her somewhat immature nature made her act impetuously, which was frowned upon by some members of the League, especially Captain Atom and Batman. However, despite her rushed judgment, she was goodhearted and well-intentioned.

The Doppelganger mystery
At one point, Supergirl started to have disturbing dreams in which she chased and incinerated men she had never seen before. She contemplated the possibility of those so-called dreams being in fact suppressed memories while she was under the government's custody. Supergirl, Green Arrow, and the Question set off to investigate this strange occurrence. They went to S.T.A.R. Labs, where Professor Hamilton assured her that she was under their care and vigilance the entire time, and that her dreams may be an expression of her traumatic experience. While leaving, the trio got attacked by robots and soldiers that linked them to the U.S. Army, and more specifically to General Hardcastle. They confronted him and he admitted to having being in charge of government experiments in metahuman and mutant studies, but he couldn't explain Supergirl's dreams. The Leaguers connected Hardcastle to Nuvo-Gen, so Supergirl and Green Arrow went there to investigate. They ascertained that Supergirl's DNA was used to create a clone, whom they trained to be a living weapon. Supergirl deduced that they shared some sort of psychic link that made her see her clone's actions. Supergirl and Green Arrow were lured into a hologram-training room, where the clone, referred to only as 'Tea', attempted to kill Supergirl and thus wipe out their psychic link, which was holding her back. Supergirl fought her off, until the entire facility blew up, seemingly destroying Galatea.

When Supergirl found out that it was Hamilton who cloned her under Cadmus's sanction, she was set to take them down. However, when trouble arose and the JL core members turned themselves over to the government, Supergirl was left in charge of the League. While the heroes where struggling to get the power back online, Galatea and an army of Ultimen invaded the Watchtower. Supergirl tried to stop Galatea from overloading the reactor, but she was overwhelmed by her clone's slightly superior strength. Supergirl stalled Galatea long enough for the reactor to reboot, whereupon she used one of its cables to electrocute her doppelganger, finally defeating her.

Years later she began to date Kyle Rayner who was sent to Earth to assist John Stewat in protecting the planet from future threats.

Powers & Abilities
Because Argoans and Kryptonians sprang from a common humanoid ancestor millions of years before and both lived on planets orbiting a red sun, Supergirl's powers closely parallel Superman's. Kara was born 16 years before her Kryptonian "cousin" but remains younger due to her time in suspended animation.

Because Supergirl was much younger than Superman, her power were not yet equal to her cousin's, though by her 21st birthday, it was evidenced how much her power had grown, as her strength seemed to be near his. She was cocky, hip, and very independent; though these traits often hindered her in her early career. She found ways to use them to her advantage. She also had over time obtained hand-to-hand combat skills after training with Shayera.

Powers

 * Infrared/Thermal Vision
 * Super Leap
 * Super Strength
 * Microscopic Vision
 * Invulnerability
 * Super Hearing
 * Telescopic Vision
 * Flight
 * Heat Vision
 * Super Speed
 * X-Ray Vision
 * Freezing Breath
 * Electromagnetic Spectrum Vision
 * Superhuman Stamina
 * Superhuman Agility
 * Superhuman Reflexes
 * Precise Muscle Control: She can mimic other peoples' voices.

Abilities

 * Genius-Level Intellect: Supergirl has shown incredible intelligence and computational abilities; her mind works sharply and with extreme speed relative to earth-humans. Her analytical powers are impressive — she is able to use her senses to read information directly from machines (and, with careful usage of her heat vision, she can even reprogram machines).
 * Master Combatant: She has been trained by Shayera in advanced martial arts and trained with the John Stewart in combat.
 * Multilingual: Supergirl speaks a multitude of languages fluently. She learned all of Earth's languages during her time on Earth. She was also taught Interlac, the universal language in deep-space, and Thanagarian by Shayera.

Weaknesses
She shares Superman's vulnerability to Kryptonite.undefinedShe is also weakened by red sun radiationundefinedand has the same problems with magic.

Exposure to Kryptonite will rob Kara of her power, cause her great pain, and prolonged exposure can kill her.

Forced under a red sun makes her rapidly lose her powers, reverting to the stature of a normal human. Artificially-created red sun radiation has the same effect although depending on the amount, it can do anything from either completely depriving her of her powers or just weakening her.

Her X-ray vision cannot penetrate lead or lead-lined walls. It also cannot penetrate inertron, the most indestructible substance in the universe. The heat of her x-ray vision cannot melt lead, unless it is a very thin lining.