At some point, Magne committed nine armed robberies, three murders, and twenty-nine attempted murders. She also had a friend who admired and accepted her for who she was.
Magne arrives alongside Moonfish and Spinner and they join the rest of the Vanguard Action Squad as they are looking down at the camp. When the squad begins its attack on the camp Magne and Spinner run into Pixie-Bob and defeat her.
When some of the students, arrive at the scene, Spinner introduces the Vanguard Action Squad and Magne asks the heroes whether she should crush Pixie-Bob's skull. This enrages Tiger but Spinner tells Magne not to hurry and also tells Tiger to calm down. After talking about Stain, Spinner introduces himself and reveals his huge sword. Tiger and Mandalay start fighting the two villains while the students leave. 
While they are fighting Spinner is distracted by Mandalay's compliments and is attacked by her claws. While she is preparing to attack him again, Magne saves Spinner by using her Quirk to pull her closer to him. Before she can attack Mandalay, Tiger steps in to save his partner by punching Magne in the face. Tiger introduces Magne and reveals all of the crimes she has committed so far. Magne jokingly says that she did not know that she was famous but Tiger continues to punch her. Magne blocks the punch with her hands. After Mandalay mentions that she is not able to reach Ragdoll, Magne smiles.
The fight continues and suddenly, Izuku Midoriya appears while smashing Spinner's "sword" to bits to inform Mandalay about Kota Izumi's whereabouts and about the fact that the villains are looking for Katsuki Bakugo. Magne deduces that Izuku must have beaten Muscular to get that information and decides to kill Izuku. However, Magne cannot reach him because Spinner throws a knife between her and Izuku, thus stopping her from pursuing Izuku further.
Magne scolds him for this action because Izuku is on the priority kill list of the Vanguard Action Squad. Spinner then clarifies that the list belongs to Tomura Shigaraki and tells Magne that Izuku was the person that Stain saw fit to save thus being a man worthy of the title of a true hero. While they are arguing, both of them are attacked by their respective opponents. Eventually, Magne is apprehended by Tiger and blames Spinner for their defeat. Kurogiri arrives and rescues Magne and Spinner, teleporting them back to the League of Villains' hideout.
After completing the mission, Magne is present when Tomura talks to the restrained Katsuki inside the League of Villains' hideout.
After Katsuki and the League of Villains watch a video clip of U.A. High School's public apology, Magne listens to Tomura explaining to Katsuki about society's current flaws and the League of Villains' battle to make a better society. After his restraints are removed, Katsuki attacks Tomura with his Explosions. Katsuki tells the League of Villains that it is pointless to try and make him change his mind as he has already been won over by the way All Might looks when he wins. Katsuki says that from the beginning he has dreamed of becoming a Hero and surpassing All Might and nothing they say will change that. Katsuki tries intimidating his captors, but Magne along with the rest of the Vanguard Action Squad are not intimidated.
Out of nowhere, Nomu appear from mysterious black liquid which takes the pro heroes off guard. Magne along with the League of Villains are teleported by the mysterious black liquid to the League of Villains' destroyed warehouse where All For One is.  All For One forcefully activates Kurogiri's Quirk which creates a portal for the League of Villains to escape through.
After Katsuki is rescued by Izuku, Tenya Iida, and Eijiro Kirishima, Mr. Compress along with Magne and Spinner hatch a plan to recapture Katsuki. Magne magnetizes Mr. Compress and Spinner pushes him, causing Mr. Compress to fly at Izuku's group. Suddenly, Mt. Lady uses Titan Cliff and intercepts Mr. Compress, which causes them to smash into each other, preventing Mr. Compress from getting to the students. Magne and Spinner prepare to throw Twice, but Gran Torino blitzes them causing them, knocking them unconscious. Tomura and the Vanguard Action Squad are forcefully magnetized by Magne's Quirk courtesy of Sensei; Magne is knocked into Kurogiri's Warp Gate by All For One and is teleported away.
In the meeting between the League of Villains and Shie Hassaikai, Overhaul chastises Tomura for having no plan and throwing away valuable and first-rate pawns (such as Muscular and Moonfish) and asks them to become his underlings, because unlike the League of Villains, he actually has a plan after gaining power. Not wanting them to be Kai's underlings, Magne attacks the Yakuza boss but is killed by Kai Chisaki using Overhaul.
Even after Magne's death, her comrades are greatly affected by her loss, especially Jin Bubaigawara, who dearly blames himself for this unfortunate event.
Tomura avenged her death by taking the arm of Kai, while Mr. Compress took his remaining arm.