WARNING: The following contains spoilers for King in Black: Gwenom vs. Carnage #2 by Seanan McGuire, Flaviano & Ig Guara, Rico Renzi, and VC's Ariana Maher, on sale now.
Earth-65's Gwen Stacy was in the heart of the city when Knull's King in Black invasion came raining down in the form of symbiote dragons. Even her best attempts to get to safety only led to the destruction following her ,and a last-ditch effort to return to her own dimension ended up bringing her best friend, Mary Jane, back to the nightmare that the primary Marvel Universe has become. Watching the people closest to her become twisted and horrifying reflections of themselves is bad enough, but to top it all off Ghost-Spider has an uncomfortably close encounter with the progenitor of the madness, Knull.
Gwen discovers that her best friend, the Mary Jane of her world, has been overtaken by the oozing symbiotic mass and now calls herself Carnage. Now faced with her best friend as the latest iteration of Knull's favorite creation, Gwen isn't sure what to think of the situation, mostly because she's horribly uninformed. She doesn't know where the attack is coming from, she doesn't know who or what Knull is, and the only thing she can focus on is saving Mary Jane from whatever it is that has happened to her.
Btut in King in Black: Gwenom vs. Carnage #2, Mary Jane's Carnage doesn't want to be saved. As she swings wildly at Ghost-Spider, Carnage lets loose a torrent of insults and pent up rage, telling the hero she only made their world a worse place before slamming her into a pool of the living darkness. As the creeping mass overtakes her, Gwen falls through an alien landscape with Knull at the center. Knull might not have control of Gwen, but he knows all about her through Mary Jane, and he shows the hero just what her best friend really thinks of her.
Knull shows Gwen memories from years ago on her own world, memories of Mary Jane being blown off by her friend who was too busy saving the day to keep up with their shared aspirations, and at times their friendship. Aside from not listening to MJ in general, the direct impact of her heroics eroded away at the trust and admiration that Mary Jane had for her, all of that frustration hiding just under the surface and waiting to erupt.
Now that Knull has given her the opportunity to let loose all that pent up anger with incredible violence, he's taken for himself the chance to turn it on Gwen in an attempt to make her give in to his will. Gwen has no intentions of becoming part of whatever it is that Knull has dominion over, and she doesn't plan to see Mary Jane stay the way she is for long, either.
Because her symbiote is synthetic, Gwen is able to stay free of Knull's influence, but that doesn't mean she's free from the chaos. Gwen pleads with Mary Jane to talk to her, but this only drives her further into the brutal madness of the Carnage symbiote.
Knowing she can't overtake Gwen and seeing that the fight is going nowhere, Carnage makes her escape, gleefully declaring that she has places to be and people to kill. Ghost-Spider takes off after her friend, but when the dust and darkness eventually settle, that might not be the right word for their relationship anymore.