New X-men 126 after Emma tricks Nova to go into the shapeshifting Stuff
Jean and Xavier are seen teaching Nova who was now a blank slate
Ernst appears later in the series and in Here Comes Tomorrow, its heavily implied that she is Nova, whom shapeshifted (due to Stuff) and was now "reformed" due to Xavier and Jean rehabilitating her.
While not the same as Red, both involved using methods to force Nova's morality to change. She gains a conscience and becomes "good" due to mental or nannite manipulation against her free will