My Hero Academia's UA Traitor was finally revealed after years of their identity being hinted at. In a surprise twist, Class 1-A's most dazzling hero, Aoyama Yuga, was revealed to be All For One's spy within the school. Aoyama took no pride in his job, referring to himself as a despicable villain once he was caught. He recently aided the heroes in their plan to entrap All For One, but a closer look at some of Aoyama's actions during the Provisional Hero License exam reveals he'd been trying to leave the villain boss's employ for quite some time.
Shortly after the first test in the exam began, Class 1-A found themselves separated by the rumbling effect of Shindo's Vibrate Quirk. Since that test hinged on teamwork, most of them began to look for their classmates immediately after they regained their bearings. Interestingly, Aoyama chose to hide behind a rock until he was found by Tenya Iida. Aoyama's cowardice was quite uncharacteristic for a student of the hero course -- but it makes sense if he was intentionally trying to fail the exam.
Unlike many of the other Class 1-A students, Aoyama has never shown any particularly strong desire to become a hero in MHA. He was born Quirkless, and as a child admired heroes as many others did. To allow their son to chase his dream, Aoyama’s parents sought a Quirk for him from All For One -- but that gift came at a terrible price. The repayment demanded by the villain was their loyalty; he ordered Aoyama to enroll in UA and then forced him to leak sensitive information to the League of Villains. On the outside the boy was living his dream life, but he continued to sink into deeper despair with every task he completed for AFO.
Spying for All For One isn't a job one could just opt out of, but as Aoyama must have realized, it couldn't be helped if he was no longer around Class 1-A because he failed his Provisional License exam. Understanding that he no longer intended to pass the exam puts his lack of enthusiasm upon reuniting with Iida -- and his actions later on -- into perspective. Upon meeting Iida, Aoyama initially scoffed at his class rep's determination to locate all of 1-A before passing the test himself, but Iida's earnest desire to serve the class reminded him of his own dreams of being a hero.
His classmate's conviction triggered a flashback; young Aoyama was questioning his parents about why he was different. Before his traitor status and former Quirklessness were revealed, it was natural to assume he was referencing his laser's side effect -- now it's clear that Aoyama was asking why he didn't have a Quirk like everyone else in My Hero Academia.
The duo traveled together, but the combined might of the other schools targeting UA meant their chances of passing were quite slim. Realizing he was slowing Iida down, Aoyama decided to sacrifice himself so his class rep could pass. He fired a continuous stream of his navel laser into the sky, creating a pillar of light that could be seen from every corner of the arena and making himself an obvious target. He advised Iida to speed through the crowd that was heading toward them and take advantage of their tunnel vision to pass the test, but his plan backfired.
Along with the rival schools that charged for Aoyama, the Class 1-A students who hadn't passed the test yet recognized the laser all too well. In an instant, the whole class had assembled around Aoyama and Iida. Using their tried and tested combo moves against their opponents, they completely decimated their rivals. The reinforcements were exactly what Aoyama and Iida needed to turn the tide, and both managed to pass by the skin of their teeth. However, in contrast to his classmates' more jubilant expressions upon passing, Aoyama simply remarked pensively "Well that means my twinkle won't stop, huh?" His job for All For One hadn't come to an end yet.
