Stan Lee had a gentleman's agreement with DC Comics never to infringe on copyrights by making an opposite-sex version of a character. Wonder Man, who seems like a male version of Wonder Woman from the sound of it, appeared in Avengers #9. He was killed off by the end and Stan Lee assured DC he would never come back.
Power Girl first appeared in 1976 in All Star Comics #58. It was not a one-time appearance, this was an ongoing character. Stan was mad, the gentleman's agreement was off, and Wonder Man came back to life in Avengers #152.
Mark Gruenwald did this gag as an in-joke to this controversy, with a female version of Power Man - Marvel's Power Girl.