In Wonder Woman #37, we saw Hecate and the old crown make a concoction out of Hippolyta's remains and a few other things giving birth to Donna Troy. She proceeded to follow their programming and lead the slaughter of all of the males on Paradise Island but what if she wasn't technically "born" then but "reborn"? The solicit for the first issue of Titans Hunt reads:
CONVERGENCE is over, but the ripples are still being felt, especially by a young precog named Lilith. What are these visions she’s having of a Teen Titans team the world never knew? And why does she feel compelled to seek out Dick Grayson, Roy Harper, Donna Troy and an Atlantean named Garth and warn them that something dark and sinister is coming after them? Who are Mal, Gnarrk, Hank Hall and Dawn Granger, and what is their connection to the others—and to the fate of every soul on Earth? This is the Secret History of the TEEN TITANS!
What if the reason no-one remembers this group of Titans is because one of the Titans' villains such as the Antithesis or Trigon slaughtered Donna Troy and made the rest of the team forget about their time together along with making the entire world(universe?) forget about Donna Troy's previous existence? Hecate, being an ancient powerful sorceress could have retained her memories of Donna Troy and fused her soul into the being that came out of her cauldron to torture Diana subconsciously. Could it be that when Diana threw her magic lasso around Donna that it awakened her previous heroic personality which is why is she is in a state of self-disgust over her slaughter of the male Amazons?