DC has a really bad track record when dealing with the Super-Women, especially after Crisis On Infinite Earths. Originally, Power Girl was the Supermans Kryptonian cousin from Earth 2. When Crisis On Infinite Earths merged Earth One and Earth Two, Power Girl survived; however, her back-story was not unscathed. A mentioned previously, the Post-Crisis Superman was the only Kryptonian survivor, so Power Girl had to find a new origin. It is obvious DC didnt know what to do with the character, so they decided that Power Girl would be a descendant of the Atlantean sorcerer Arion. Yep over night Power Girl went from hanging out in space as as super-powered alien to chillin under the sea as mystical Atlantean. This jarring retcon remained canon until the first issue of Infinite Crisis released in 2005. Infinite Crisis re-established Power Girls original origin, as she is reunited with her cousin, Superman of Earth Two, who disappeared into a pocket dimension at the end of Crisis on Infinite Earths. Alls well that ends well.