WARNING: The following contains spoilers for Captain Marvel #16, by Kelly Thompson, Lee Garbett, Tamra Bonvillain and VC's Clayton Cowles, on sale now.
Captain Marvel #16 finally brings the series’ latest storyline, “The Last Avenger,” to a close. It all began when a new villain named Vox Supreme forced Carol to go after the Avengers and defeat them in battle. With the lives of countless Kree refugees on the line, Carol had no choice but to take those commands, so she concocted a plan to save her friends while still following orders. She hid them in the pocket dimension located inside Singularity and brought Vox Supreme something decoy clones created by a secret S.H.I.E.L.D. project.
Everything comes to a head in Captain Marvel #16, as Carol discovers Vox Supreme’s endgame. The villain is planning to create a new race of Kree warriors — but before he has a chance to do so, Carol Danvers shows us what, exactly, Vox plans on creating when she is transformed into a frightening, Hulk-ing monster.
In Captain Marvel #15, Vox Supreme revealed what he planned to do with the bodies of the Avengers. After harvesting their DNA, he will use it as the foundation to create a new race of Kree warriors. With the power of the Avengers coursing through their veins, these new Kree will be unstoppable and they will rule the entire cosmos in the name of Vox Supreme. His serum is ready in Issue 16, but he doesn't get the chance to use it. Carol breaks free of her confines and engages the villain in a fight.
During the confrontation, Carol ends up accidentally covered in the experimental serum. Worse still, she becomes infected with what is about 20 times the dose it would take to create one soldier. As a result, she becomes a literal one-woman Avenger army, but the results are far more disconcerting than anyone anticipated. The serum doesn’t just give her the abilities of the various Avengers -- it gives her their personalities and voices, too.
Therefore, her body grows to the size of She-Hulk, but only roughly half of her. She is grotesquely deformed, as evidenced by the other heads that pop up out of her body — and she has incalculable power coursing through her. Thankfully for Carol, the transformation doesn’t last long. After throwing up some of the serum, she manages to control everything inside her and summon Mjolnir to finally defeat Vox Supreme once and for all.
When the battle is won, Carol uses her own cosmic powers to burn the rest of the serum out of her system and return to normal. It was a short transformation, but Carol Danvers really became another pillar of power in the Marvel Universe, if very briefly. On her own, she is Captain Marvel, one of the most powerful Avenger there is. Then throw in the abilities of Thor and She-Hulk, and she becomes something we have never seen before. It just turns out it’s the stuff of nightmares.