Dabi watches a public broadcast about the news of the Hero Killer's capture. Inspired by Stain's ideology, Dabi decides to move towards the organization that was widely believed to harbor Stain's cause: the League of Villains.
Giran brings Dabi and Himiko Toga to the League of Villains hideout. Dabi comments that the group's leader, Tomura Shigaraki, is gross looking. Tomura is displeased with the recruits and immediately asks Kurogiri to remove them. Kurogiri refuses and Giran introduces Dabi as a criminal who has not done any flashy crimes but follows Stain's ideology. Dabi says he is unsure about the league's motivations and asks if they would really let a crazy girl like Himiko join.
Tomura remarks that she introduced herself and asks Dabi for his name, but he says he will only reveal it at a later time. Dabi goes on to say he will make the Hero Killer's will a reality. Tomura becomes wildly irritated by Dabi and Himiko's comments about Stain, enough so to attack them. Dabi and Himiko prepare to defend themselves, but Kurogiri steps in and uses his Quirk to stop them from coming to blows. Tomura storms off and Dabi complains about his attitude. Kurogiri asks Giran and his recruits to wait for a proper answer at a later date.
Dabi is eventually recruited into the League of Villains and assigned to lead a team of elite villains called the Vanguard Action Squad. Tomura acquires equipment for the team and has them pick it up at an unknown warehouse location.
Himiko announces there is enough gear for everyone and they should bring it along on their mission. Muscular adds they need to hurry up, but Mustard disagrees because the team has been ordered not to rush or do anything too flashy. Dabi agrees and says that Tomura acted like a brat and attacking when they first met, but now he's suddenly taking charge. Dabi proclaims that their mission will be a warning shot that will tear down false heroes from their shining pedestals and drag them back to earth in order to create a new future for the world.
The next day, Dabi and six other villains secretly arrive on the Wild, Wild Pussycats forest reserve where U.A. High School students are training. The Vanguard Action squad observes the campsite from a high vantage point. The members of the group start to argue about their next move, so Dabi tells them all to shut up. He goes on to say that Tomura was foolish for trying to attack the U.S.J. with a band of low-level thugs and that it's much better to use a small group of elites. Dabi announces the League of Villain's first task is to strip away the student's sense of security.
The Vanguard Action Squad begins their assault the next evening. Dabi uses his quirk to set the Beast's Forest ablaze in blue fire. Dabi believes the time has come for the Vanguard Action Squad to tear the false heroes down from their shining pedestals.
Dabi keeps the fire going while the other villains search for Katsuki Bakugo. Twice makes clones of Dabi so he can distract the U.A. teachers. Dabi waits outside of the base camp building and surprise attacks Shota Aizawa on his way out. He blasts Eraser Head with an explosion of blue flames. Eraser Head evades and erases Dabi's quirk by looking at him. He overpowers the villain and pins him to the ground before interrogating him for information about his allies. Dabi refuses to comply and gets free once a few of the students arrive. Eraser Head goes to restrain Dabi again, but the clone disappears as Dabi taunts the latter.
Dabi tells Twice the clone was defeated too fast. Twice rebuffs Dabi's claim. He comically argues until Dabi orders him to make another clone to keep the Pro-Heroes at bay. Another one of Dabi's clones attacks the base camp again. He blasts one of the classrooms and is quickly restrained by the Blood Hero: Vlad King. The clone goads Vlad King until Eraser Head arrives and destroys it.
Mr. Compress is able to successfully capture Katsuki and radios the team to rendezvous. Twice complains and Dabi argues that Mr. Compress did a fine job. Dabi notices Yuga Aoyama hiding behind a bush, but before he acts, Twice reminds him to call back Nomu. Twice had reminded Dabi to unleash Nomu on the students earlier. Dabi remembers the Nomu was designed for him and will only react to his voice. He signals the Nomu while he and Twice walk to the meeting spot.
Dabi and Twice meet Himiko first. Dabi asks how her mission went and Himiko replies that she was only able to collect one sample of blood. As Twice and Himiko begin to banter back and forth, Dabi notices a trio of students tackling Mr. Compress out of mid-air.
Dabi orders Mr. Compress to move aside and he does so by using his compressing quirk on himself. Dabi throws a fireball that burns Mezo Shoji and Izuku Midoriya. The other villains attack the student and Mr. Compress motions to give the captured students to Dabi. He meant to keep their compressed marble bodies inside his pocket, but Mezo stole them.
Kurogiri arrives to evacuate the villains. Dabi refuses to leave without Katsuki, but Mr. Compress reassures him he was hiding the real marbles the entire time. Yuga shoots Mr. Compress in the face and he drops the marbles out of his mouth. Mezo is able to retrieve Fumikage Tokoyami, but Dabi secures Katsuki's marble before Shoto Todoroki reaches it. Dabi taunts Shoto's attempt as he commands Mr. Compress to confirm Katsuki's body. Katsuki reverts to his normal body with Dabi's hand around his neck. Dabi calls checkmate and the villains disappear within the warp-gate.
Having completed their mission, Dabi and the Vanguard Action Squad return to the hideout. They restrain Katsuki and bring him before Tomura. 
Tomura tells Katsuki about the League of Villain's goal to reform hero society. Then he asks Dabi to remove his restraints. Dabi argues that Katsuki will fight, but Tomura asks him to do it anyway. Dabi orders Twice to remove the bonds and then Katsuki immediately blasts Tomura in the face with an explosion. Katsuki tells the League he'll never join them because he wants to be a hero like All Might. 
Magne comments that Katsuki is clever for realizing his own value to the villains. Dabi argues that he's a fool for fighting. Tomura puts one of his hands back on and requests that nobody harm Katsuki. Tomura asks All For One to lend him his power and then orders Compress to restrain Katsuki. 
The League of Villains are interrupted by the unexpected arrival of what sounds to be a pizza delivery. Then All Might suddenly bursts through the opposite wall with Kamui Woods and the latter restrains all the villains with his Lacquered Chain Prison technique. Dabi believes he can easily free himself from the wooden binds and tries to ignite his flames. Gran Torino flies in and stops Dabi by knocking him unconscious with a swift kick to the head. 
Dabi and the other villains are saved when All For One warps them to the destroyed Nomu Factory.  All For One activates the Quirk of an unconscious Kurogiri and orders the League of Villains to capture Katsuki and retreat. Mr. Compress uses his Quirk to compress Dabi's body into a marble. All of the villains are forced to flee the battlefield when All For One uses Magne's Quirk to force them into the Warp-Gate.
Three weeks following the battle in Kamino Ward, the League of Villains members separate in order to conceal themselves and recruit like-minded individuals to their cause. Dabi enters an alleyway, hoping to find recruits there.
The low life thugs threaten to kill Dabi and he recognizes that they're nothing but weak thugs. He tells them to get out of his way and then burns them all to death with his Quirk. Dabi says that they're garbage and the least they can do is become kindling from his flame. 
The League of Villains engages a Police convoy carrying Overhaul inside one of the trucks while he's restrained and strapped to a medical bed. Dabi tells Spinner to stop driving erratically because it's making him car sick. He maintains his composure and attacks the convoy with a large flamethrower stream, prompting the Sand Hero: Snatch to appear from within one of the trucks.
Dabi recognizes Snatch as a famous hero while Tomura fights him. Tomura crashes several of the trucks into each other and then Dabi confronts Snatch himself. He taunts Snatch for being a hero that always needs to jump in to rescue others. Snatch recognizes Dabi as the villain associated with a string of murders where the corpses burned. Dabi's is excited to hear about his notoriety.
Snatch attacks Dabi with a sand tiger move and Dabi counters with large fire blast. While Snatch is distracted, Mr. Compress uses his Quirk to trap him inside a marble with Dabi's flames. Mr. Compress accidentally burns himself and then asks Dabi if Snatch's sand will burn. Dabi believes Snatch can only transform his upper body into the sand and will likely die while compressed.
Tomura exacts his revenge on Overhaul by destroying his arms. Spinner warns his allies that police reinforcements will arrive soon. Dabi, Mr. Compress, and Tomura walk back towards the truck as the flames from their destruction burn in the background.
At Hidamari Kindergarten on the same day as the JP Billboard Chart release, Dabi tells High-End that it is the first intelligent Nomu and he expects good results. High-End attacks the No. 1 & 2 Pro Heroes: Endeavor and Hawks. Dabi watches from within the city limits when Endeavor narrowly wins their fight. The two Pros are injured and before they can request for help, Dabi confronts them himself and greets Endeavor. 
Dabi confronts the two heroes and traps them within a wall of fire. Endeavor recognizes Dabi as the villain who murdered Snatch and Dabi claims he has no idea who he's talking about. Dabi tells Endeavor he wants to talk while they have the opportunity. Hawks stands up to Dabi and the latter claims he wouldn't try and defeat the two top heroes alone. Then Dabi says that they're both on death's doorstep and decides to attack. Mirko interrupts and attacks Dabi from above. Her fearsome stomp keeps him at bay and Dabi decides to retreat using the Warping Quirk. Before he leaves, Dabi calls Endeavor by his real name and tells him not to die.
Afterward, Dabi meets with Hawks to discuss High-End's attack. Hawks is upset with Dabi for not keeping to their original plan and holds a blade to his neck. Unfazed, Dabi replies that Hawks wasn't supposed to bring someone as powerful as Endeavor. He questions the lack of casualties from the battle, insisting that a villain sympathizer wouldn't have acted in such a heroic way. Hawks explains he has to keep a Heroic appearance to the public to make himself more useful to the league of villains. Understanding, Dabi walks away and tells Hawks he can't meet their leader yet, but he'll contact him again in the future.
While walking towards the harbor, Dabi recalls Snatch and is seemingly moved by the hero's last words to him. Dabi says thinking about all the families he's affected has nearly driven him crazy. He wipes some blood from the patch underneath his eye as if he was crying.
Prior to the Hero Billboard JP, the League of Villains has seen better days. They're barely scraping by with no funds and have resorted to stealing from other criminal groups and living in a run downed building. Rather than partaking in theft, Dabi spends his time trying to recruit new members. He returns to the filthy hideout and berates his allies for sitting around doing nothing.
Twice replies that Dabi just burns everyone he meets. Dabi claims he burns them because they're ambitionless trash and Himiko taunts him for being a poor judge of character. Spinner confronts Tomura over the state of the League and admits he's only here to fill his empty heart with a new purpose. Dabi taunts him by saying he's just a hollow cosplayer of Stain.
They're interrupted by an intense rumbling that brings the villains outside. The League of Villains come face to face with a giant claiming its searching for All For One's successor. Dabi questions the identity of this titan and Tomura claims he's the secret weapon Kurogiri got captured trying to retrieve. The giant quickly overpowers the League, but the voice of All For One's doctor plays from the beast's radio. 
The Doctor explains that the giant is named Gigantomachia and he is All For One's ex-bodyguard. Gigantomachia went into hiding before All For One's defeat and the Doctor claims this meeting was all apart of his plan. Dabi replies that the big guy isn't exactly a generous gift and lights up his flames. Dabi bathes Gigantomachia in blue flames. Shocked, Dabi watches as the giant brushes off the fire and Himiko tells Dabi his attack didn't work.
A recording of All For One's voice soothes Gigantomachia and calms him down. The Doctor warps the League to his lair using the warping Quirk from Kamino. Dabi immediately notices the Nomu housed in the lab. The Doctor commends Dabi's sharp eye and introduces himself as Daruma Ujiko. Annoyed, Dabi asks why the League is at the lair and the Doctor replies that they must prove themselves if they desire his support. 
In response, Tomura explains his past and why he desires to destroy everything. Bored, Dabi stands by with the others who don't appear to quite understand Tomura's distortion. The Doctor accepts Tomura but he will not fully support the League until they defeat Gigantomachia. Dabi refuses to help because he wants to put more time into recruiting a potential ally. Tomura says he's excited to see who he brings and the Doctor tells Dabi he can help test a High-End for him. 
Following the events in Fukuoka, Dabi hides out on the border between Iwe and Shiga. He's warped to Deika City by the Doctor and regroups with the others for a war against the Meta Liberation Army. Dabi's annoyed they dragged him into their rescue mission and this angers Twice. Himiko notices someone approaching the group and Dabi readies his flames. It turns out to be an escort, the Pro Hero Slidin' Go.
Slidin' Go leads the villains through the seemingly abandoned city where they eventually meet with Koku Hanabata and Chitose Kizuki, two top executives of the army. Koku begins the Liberation Army's Revival Celebration and dozens of citizens suddenly ambush the villains. 
Dabi appears to avoid direct combat while dodging various Quirks aimed toward the League. Spinner comments that no matter how many warriors are defeated, they just keep coming in waves. Dabi replies that Spinner hasn't defeated a single one yet. Koku Hanabata uses his campaign van to announce that Chitose has perished at the hands of Himiko. The warriors are enraged and swarm at Tomura, who counterattacks by killing them all with a single swipe of his hand.
Impressed, Dabi says its about time he got serious about fighting when suddenly a hooded man tries to crush him using two giant ice gauntlets. Dabi avoids it and admits that he's gotten stronger and now he can tell at a glance this new bruiser is tough too. Geten asks Dabi why he hasn't used his wide range of flames to attack yet, suggesting something might be wrong with his abilities.
Dabi smirks and counterattacks with a wave of flames that melts his opponent's ice. The ice warrior collects ice from all the nearby buildings and collects it into one massive frozen figure. He claims to have been perfecting his Quirk without school his entire life. Dabi taunts him for living a sad life and the elements of their Quirks collide, splitting the battlefield.
The blue flames prove more ferocious and hold the advantage against Geten's ice. Dabi taunts his opponent, calling him outmatched since his ice is all gone. Compress struggles nearby against some of the other warriors and asks for help. Dabi asks why he should help when an army of twice clones is heading their way. The doubles fight to protect Dabi and Compress from the other warriors. Many of them decide they should try and double Dabi but Compress urges them to save some fodder for when Gigantomachia awakens.
Geten takes out much of Twice's Sad Mans Parade with a barrage of ice. Confused, Dabi asks if this town specially manufactures ice. The Iceman explains that he can lower the temperature of the town's water supply in order to generate more ice. Dabi calls him obnoxious for not leading with that in the fight and Geten responds by claiming the Liberation Army will create a world where status is attained by the strength of one's Meta Ability.
Dabi believes that Geten's words of sheer strength sounds miserable and rudely asks him to keel over and die. The ice warrior claims Dabi will be the one who dies, as he can smell his burning body from here. Geten has been observing Dabi's Quirk and believes his body is not compatible with it. Dabi's blue flames eat away at his body, meaning its difficult for him to fight prolonged battles. Compress wishes they could sick Gigantomachia on the iceman and worries about Dabi's fate. Doctor Ujiko notices the League is in peril and awakens the giant early. 
Despite his injuries, Dabi fights on against Geten in a battle of elements. Their fighting continues until both fighters are worn down and Gigantomachia enters the city. The giant proves far more powerful than the army can contend with and Compress realizes they were foolish for underestimating him. Compress asks Dabi to finish up this battle so they can save Tomura before the giant reaches him. 
Worried for his own leader, Geten flees the area and tries to stop the giant on his own, only to be easily cast aside. Annoyed and smoking from his wounds, Dabi claims he was close to burning that icy freak up before he fled. Tomura achieves victory against the Meta Liberation Army's leader and obliterates half the city with his Quirk. Re-Destro concedes and hands the Liberation Army over to him.
The League of Villains all survive the Revival Party and recover for a week in a new mansion. Dabi meets back up with Hawks and confirms he killed a man as asked. He isn't sure its actually Best Jeanist but invites him to the next meeting anyway.
While dining on Sushi, Compress claims that this is the calm after the storm. Dabi replies that Compress didn't do a single thing in the battle. Spinner asks Dabi for his sushi and Dabi lets him have it because he hates fish.
Dabi and all his allies are led underground by Skeptic and Trumpet of the Liberation Army. With Tomura as its new leader, the League of Villains and the Meta Liberation Army merge to become the Paranormal Liberation Front. Dabi is one of the nine lieutenants appointed to Tomura and will receive a team tailored to him. 
At some point after the clash, Dabi and his allies (excluding Tomura and Geten) are present at a meeting in which Hawks informs them of Endeavor's decision to take on two new interns other than Shoto. Dabi comments that he feels like the students haven't changed ever since the Training Camp incident.