Daring Damsels' Dream Detours: Kara from Krypton vs Herself!

Supergirl and Power Girl were vulernable to such things as Green Kryptonite. However, they were also prone to be attacked from within, from their dreams.  Each Maiden of Might had scores of adversaries to face, such as the mental madmen known as Universo and Brain Wave, who attempted to distort their reality. Yet their most insidious enemies were their own mirror images! 

Throughout Supergirl's history, she faced darker versions of herself created through various means such as Red Kryptonite.. while for years aboard her ship, Power Girl faced a lighter, unrealistic version of herself.

While Power Girl had a copy of herself exist while she was aboard her Symbioship, in the form of a warrior maiden of the city of Asgard high above Earth-Two. This blonde Asgardiam mind-melded with the Power Girl of post-Crisis Earth in 1945. Each of these women, seeing their lives as pale shadows of their respective Kara, sought to create their own legends as the next Supergirl and Power Girl.

Lesla-Lar utilized a brain-wash helmet in order to distort Kara Zor-El's memories of her life as Linda Lee. Trading places with Kara, Lesla assumed the identity of Supergirl and fooled both her cousin Superman and his arch-foe, Lex Luthor. It was Luthor whom she conspired with, then turning her attention to a few Kryptonian criminals. After freeing them from the Phantom Zone, they betrayed her, by using one of their weapons to atomize her body. Lesla's psyche remained alive, however.

Years later, Lesla as an energy construct tried to defeat Supergirl by manipulating minions, including another Phantom Zone prisioner named Shyla Kor-Onn. When these schemes failed, Lesla then tried to attack Supergirl from within her own body, using dreams to project realistic illusions. Supergirl fought back, exercising her superior will power to rid herself of Lesla's mental influence for good.

Kara Zor-L fought a similiar mental influence for several decades aboard the Symbioship. This ship's devices crafted a future Kandor envisioned by her parents of a Krypton-Two that had not exploded. This mental conditioning made Power Girl  prone towards its influence, when it attempted to replace her with another Kara. At this time, the Asgardian Kara Zor-L had departed back to her post-Crisis Earth.

Power Girl's superior will power fought back, ridding herself of the Symbioship, and later provided her the means to track down and out-think the dream-manipulating criminal Brain Wave.