Before the OC killed himself he decided to create a successor to complete what he never finished (fixing Equestria's broken system of capitalism and alicorn supremacy). He didn't do this alone, as he needed the help of Chrysalis (who agreed under the condition that he fed her any love that he had, which was not that much) to create a clone of Trixie. Chrysalis already knew how to make clones and she was easily able to get a picture of Trixie and one of her hairs. He then transferred all of his dark magic (which came from his red eyes) to the Trixie clone to make her more powerful than the original.

Anti-trixie, Dark Trixie, Mean Trixie, fuck call it whatever you want. She pledged to continue what Manerg had begun and started by killing Chrysalis. Manerg killed himself. Octavia was the only pony who attended the funeral, and she was relieved after being afraid that he would have eventually killed her.

I could have just corrupted the original Trixie, but that would have failed because her friendship with Starlight and the others was too strong and she would have inevitably turned on me.

Whether Anti-Trixie succeeds or not will forever remain a mystery, because I never lived to see it.