Shigaraki's attempt to persuade Bakugo was met with biting insults and flash grenades. Despite his first assumptions, the blonde boy was far harder to crack than he thought. Begrudgingly, Shigaraki gave in and asked for his master's help. All For One advises his pupil to be patient above all. Most people couldn't be swayed to villainy in a single day.
All For One decided to strike Bakugo at his very core. He stole Explosion and rendered the boy quirkless. He told Shigaraki to play the waiting game: let Bakugo wear himself out, and the helplessness would sink in. Bakugo got a taste of this almost immediately.
As All Might battled All For One, Bakugo remarkably saw his classmates flying above the battlefield. They'd come all this way to save him. However, they weren't aware of his stolen quirk. So when Kirishima held out his hand for Bakugo, he could do nothing but stand there. Even as his master was defeated, Shigaraki intended to follow his words faithfully and dragged his captive through the warpgate. Dabi questioned how a quirkless boy could be useful to the League, but the leader insisted All For One would break out in due time.
For months, Bakugo was locked up in solitary confinement. While the League fed him, he was deprived of any news, entertainment or interaction. No matter how many times he tried to escape, he kept failing. He simply didn't know how to function without his quirk and had no resources to speak of. If Izuku had been in his position, would he have escaped already? He managed without a quirk for fourteen years.
Eventually, the League moved on to the next stage of their plan. They wanted to give Bakugo a taste of their lifestyle. Occasionally, they escorted him outside and forced him to witness their crimes. Even as a quirkless person, they still bound him and placed a tracker on him.
Constantly, Bakugo was getting caught in the crossfire as the League clashed with other criminals. Narrowly avoiding death was becoming a common occurrence. He couldn't defend himself, and his frustration was boiling up. At the same time, he was disgusted by the new villains he encountered, like the Creature Rejection Clan. They almost made the League look good in comparison.
He wanted nothing more than to punch the supremacists in the face. However, his restraints wouldn't let him. This lead to the first turning point. Shigaraki saw that Bakugo shared a common enemy and encouraged his anger. He offered to briefly take off his restraints so he could beat the supremacists up. Bakugo found himself increasingly in the same scenario and was tempted by it.
Despite his efforts to be patient, Shigaraki was not All For One. He found Bakugo's conversion too slow, so he made a bold move. When Bakugo returned to his cell, Twice and Toga created their quirks to create his imposter. The League used this imposter to frame Bakugo for various crimes and create fake evidence for his "new villainy."
The League attempted to make it believable, such as the clone only doing minor crimes and still acting disrespectfully towards them. They created the narrative that Bakugo was slowly warming up to the League and willing to be their lookout. Izuku and his parents tried to preach this was out of character for Bakguo, but not everyone saw it like that. They saw Bakugo needing to be chained to the podium like a feral animal. Not to mention, Bakugo didn't show obvious "remorse" for All Might's retirement. The public was split on whether it was genuine or fake.
As a precaution, the authorities promised to investigate and arrest Bakugo for questioning. The possibility of a false prosecution was suddenly on the table. Bakugo's escape plan had become far more complicated. Simultaneously, he needed to find an opportunity to escape the League and gather evidence for his innocence. After much thought, he decided Toga or Twice was his best bet. If he could drag them to the authorities and make them confess to framing him, he would be home free.
However, his plan wouldn't be easy. The League was constantly putting themselves in harm's way. It was a challenge to simply keep Toga and Twice alive. Most recently, Shigaraki had gotten into a losing battle with Gigantomachia. Bakugo could barely do anything but try not to get crushed.
After being the giant's ragdoll, he finally had enough. Bakugo called them idiots and said their strategies were impractical. He didn't want to help his kidnappers, but he was tired of getting hurt. He helped devise a plan to defeat Gigantomachia. Despite some progress, they couldn't land the finishing blow.
Doctor Ujiko offered Bakugo a minor quirk so he wouldn't feel useless. Begrudgingly, he agreed. He was given "Pain-killer"; a quirk he could only project onto someone else. Like its namesake, it gave the target an adrenaline rush and numbed their senses. The doctor ensured it was a support quirk, so Bakugo still depended on his teammates. With this slight advantage, the League finally defeated Gigantomachia.
However, it was short-lived. The Liberation Army soon challenged the League, and Bakugo had to do it all over again. Relying on the League for survival, the boy had to accept them as comrades. He protected Toga during the battle, as he needed her alive to prove his innocence. However, Curious was determined to kill her. As the journalist monologued about quirk counselling, Bakugo saw a human side to Toga for the first time.
He was shaken further when Toga transformed into Uraraka. Rationally, he knew what he was seeing, but his emotions were getting the better of him. He rushed to help "Uraraka" as Curious had her on the brink of death. He used Pain-killer on Curious in overdrive. She had too much adrenaline and ended up becoming dizzy. This allowed Toga to use Zero Gravity and kill her. Bakugo was stunned, never intending to be an accomplice to murder.
Eventually, the League was victorious and joined forces with the Army. As propaganda experts, the League allowed the Liberation to take over Bakugo's conversion. He was treated "better," such as being given a small apartment. However, he was still supervised 24/7 and not allowed any communications. The Army members played to Bakugo's insecurities about his quirklessness and need to be a strong hero. Their ideology was more convincing than Shigaraki's vague ideas, such as people having more freedom to use their quirks.
The Army promised Ujiko could give him an offensive quirk if he promised to do "small jobs" for them, such as helping with training sessions for army members. Like Shigaraki, Bakugo was placed into a tank to undergo surgery. Ujiko removed the Pain-killer quirk and replaced it with his new quirk
However, he didn't tell Bakugo that he preserved Landmine from Curious's body. He placed the explosive ability into him to remind Bakugo that he was a killer and "no different from the League." Additionally, the doctor secretly placed the second power of Self-destruct. Like Lady Nagant, Bakugo could be killed if he tried leaking the League's secrets.
During the raid, Bakugo was woken up from suspended animation. He saw the heroes fighting in the distance and considered running for it. At this point, All For One had possessed Shigaraki. He blackmailed Bakugo into staying.
He explained his Self-destruct quirk. On top of that, he threatened to fly over and decay UA High if Bakugo didn't come with him. Witnessing Shigaraki destroy whole cities, he obeyed. Together, they flew to Tartarus prison. Bakugo stood aside and simply watched the chaos. He didn't know what else to do. Sneering, All For One praised him for finally understanding the stakes.
After Japan's collapse, Bakugo was technically given "freedom of movement" for the first time. However, due to his other quirk, he still had to follow orders. On top of that, his Landmine quirk wasn't ideal. He needed to prepare ahead of time and people to act as his bodyguards. In the end, he still relied on the League in battle.
Once, he numbly asked All For One to switch out Landmine for Explosion. However, the top villain laughed, saying that was unnecessary. He claimed he already had an explosive ability and could be satisfied with that. Sarcastically, All For One said Landmine made Bakugo a team player and taught him something his teachers failed to do
Finally, the League got Bakugo to do their dirty work. All For One sent him to take down villains threatening the League's agenda. Even if the mastermind freed them, he knew not every inmate was grateful and wanted power for themselves. Despite his circumstances, Bakugo tried to act as a vigilante.
He kept his enemies alive so the police could arrest them later. However, Bakugo had been desensitized to violence and could get carried away. On top of that, his enemies were the worst of the worst: murderers, terrorists, and rapists. On one or two occasions, Bakugo lost his temper and killed someone. He found a twisted friendship with Dabi, as they were apathetic to their teammates and happy to mow down lowlifes. Dabi's blue flames were the closest thing to seeing Explosion in action again.
One day, Bakugo was hiding from a fearsome hero. The mysterious figure had been sweeping the area, knocking out villains with single blows. As Bakugo caught a glance, his heart was in his throat. He recognised the green hair protruding from the mask. When had Izuku become so powerful? How did he have multiple quirks? Bakugo never thought he'd be here. The two stood on different sides of the law—him trembling in fear of Izuku.
Out of fear and shame, Bakugo couldn't bring himself to face Izuku. He snuck away, but his childhood friend spotted him turning the corner. As Izuku tried to find Bakugo's hiding spot, he tearfully begged him to come home and how he never gave up on him. He stuttered about Bakugo's dreams of being a hero growing up and how he can still fulfil them. For a moment, Bakugo is tempted by Izuku's words, but he can feel the self-destruct quirk whirring in his body. The blonde boy uses Landmine to collapse the building around him and create a distraction for his escape. Bakugo wished Izuku didn't have his excessive need to help everyone and stayed away for his own good.
While Bakguo had escaped Izuku, his allies had been arrested in the dozens. Over time, the heroes were evening the numbers.
Due to this, All For One's fanatic followers were becoming desperate. They heard how Curious had previously used Landmine. It could allow them to martyr themselves, whether to avoid capture or kill someone as a last resort. At first, Bakugo refuses to use Landmine on a person. However, he became nervous about triggering Self-destruct. He convinced himself he didn't care if these scum died, and they asked for it.
During the final battle, Bakugo finally met his old classmates. His closet friends were guilt-ridden that they never found him after All Might's final stand. Kirishima called himself useless for not realising Bakugo was quirkless when he held his hand out. Meanwhile, some students were less sympathetic. They didn't know him for long and remember him as an arrogant bully. Perhaps he was always suspendable to villainy, even without his kidnapping.
Aoyama begged Bakugo to direct his anger at him and leave their classmates alone. The blonde boy eagerly agreed, badly injuring the UA traitor. Eventually, Bakugo felt disgusted at himself for torturing Aoyama and tried to figure something out. Finally, he realized a loophole in his self-destruct quirk. He couldn't outright leak the League's secrets, but a loss of will and someone else defeating him wasn't enough to count as a betrayal. He let himself get distracted, and 1-A knocked him out.
Everyone felt terrible for Bakugo being kidnapped and failing to save him. However, he had killed one too many people. He still needed to be held at trial. Due to his overwhelming factors, Bakugo was given a reduced prison sentence and mandatory therapy.