Izuku Midoriya & Toru Hagakure vs. Yuga Aoyama

Izuku Midoriya & Toru Hagakure vs. Yuga Aoyama is the battle between Deku and Invisible Girl against the newly discovered "U.A. Traitor", Can't Stop Twinkling.

Prologue
After Deku has returned to U.A. to rest, he and Class 1-A are informed by All Might of Tomura Shigaraki's battle against Star and Stripe, and that they now about a week to prepare until he is complete for their final battle. The classmates proceed to head out into the courtyard in front of the school to train amongst themselves before they head out to continue their search for the villains. During a break, Deku decides to go for a quick stroll, with the intention of looking for someone.

Meanwhile, Invisible Girl had secretly followed Can't Stop Twinkling and his parents into a corner of the U.A. forest, having noticed that he's been looking especially down ever since the end of the Paranormal Liberation War, and even moreso that even after bringing Deku back, he hasn't smiled once. She overhears the conversation between Can't Stop Twinkling and his parents where she learns a devastating truth: Can't Stop Twinkling is the "U.A. Traitor".

Despite being in shock, she continues to listen in as the Aoyamas hysterically tell their son that they have received another order from All For One, which is for him to lure Deku somewhere alone, so that he may ambush him. The Aoyamas continue to profusely apologize for putting Can't Stop Twinkling in this position, reminding him of the threat of death if they do not comply, and bringing up the fact that All For One had given the Navel Laser Quirk to a Quirkless Yuga. Invisible Girl panics, thinking about how she needs to tell someone about all this, when she spots Deku nearby approaching.

As Can't Stop Twinkling breaks down in tears over being unable to do anything to truly save his parents, the three are caught off guard hearing a rustling in the woods, discovering Invisible Girl accompanied by Deku. He reveals that Invisible Girl had told him what she just heard, while the parents attempt to feign ignorance about it all. A depressed Can't Stop Twinkling thinks about how he never said anything when they went to rescue Deku, while Deku responds that he came looking for him because he noticed how gloomy he was and wondered if something was wrong. Hearing these words, Can't Stop Twinkling, despite his parents pleas not to, sorrowfully admits that he was the one who helped the League of Villains during both the U.S.J. Incident and the Vanguard Action Squad Invasion, declaring himself a "despicable villain."

Battle
With their secret now exposed, the Aoyamas quickly grab ahold of their son, making a break for it further into the woods, with Deku and Invisible Girl giving chase. As this is going on, Can't Stop Twinkling thinks about all the pain his parents have gone through, all for the sake of making him happy by giving him a Quirk, and all the terrible things he has done, including betraying his classmates, just to keep them safe.

Believing there is nothing left to lose, a tearful Can't Stop Twinkling states to Deku that when he read his letter and learned that he was also Quirkless, it drew him into utter despair. During this, Deku's Danger Sense goes off, realizing he is about to attack and tries to yell at him to stop, but he won't listen, as he prepares to fire a Navel Laser directly at Deku, with him getting ready to counter with a Full Cowl.

However, surprisingly, Invisible Girl jumps in the way directly into the laser, protecting Deku and using her Quirk's Warp Refraction ability to redirect the laser into a nearby tree, to the two boy's shock. As her body starts to steam from the laser's effects, Invisible Girl reminds Can't Stop Twinkling that her body lets her refract light. She confronts him, reminding him of how many times they could've been killed, and how all of Japan is screwed up now, and as her face starts to emerge for the first time, tearfully asks what he was thinking the whole time living with them at school.

Can't Stop Twinkling can only continue to cry unable to answer, while his tearful parents rush to his defense, trying to tell him they have it all wrong. But before they can explain any longer, Deku uses Blackwhip to sprout three tendrils, two of them wrapping around the Aoyamas, and the third around Can't Stop Twinkling, who he also pins to the ground. Deku tells Can't Stop Twinkling that Invisible Girl did him a favor by stopping him from hurting anyone else, and with tears in his eyes as well, tells him to just let this all be over now.

Aftermath
The Aoyamas are promptly taken into U.A., where they are put into police custody upon discovering the treachery. They are interrogated in the U.A. A.V. room by All Might, Detective Naomasa Tsukauchi, and the U.A. staff, with a devastated Class 1-A also accompanying them, bluntly refusing Nezu's request for them to leave. The class all voice their opinions toward Yuga, with Mashirao asking him what he was planning to do if Toru didn't expose him, Eijiro begs him to say it’s all just a lie, while Yuga can do nothing but sorrowly listen.

After the parents proceed to explain their limited communication with All For One, and how they were threatened with death if they ever tried to go to the police, they beg them to let Yuga go because he had no idea. He then breaks down, thinking about how everyone could've been killed, yet still had the nerve to try and smile with everyone as friends, looking at Izuku and just seeing himself as a complete villain.

However, Izuku retorts, reminding him of trying to save Katsuki during the Training Camp, as well as reminding him of his cheese message, which he realizes now was a cry for help. He states that he knows he was just another person manipulated by All For One, but that he never truly had villainous intentions and wants him to prove himself, extending his hand and telling him he can still be a hero.