League of Villains

The League of Villains (敵連合) is a group of organized villains that is made up of both weak and powerful villains and are the main antagonists of the series. The creator of the alliance is All For One, with Tomura Shigaraki being the leader of the alliance in his place while Kurogiri acts as the second in command of the alliance. The mission of the League of Villains is to murder All Might.

History
The size of the League of Villains is estimated to be 75 (however, after the events at the USJ, the size of the alliance is dramatically decreased due to the majority of the villains belonging to the alliance along with Nomu being captured and detained by the Police). However, after Stain's defeat and capture, many villains inspired by him (such as Himiko and Dabi) sought out the League of Villains to join it since the organization was believed to harbor Stain's ideology; thus the League of Villains has increased in numbers.

Unforeseen Simulation Joint Arc
The League of Villains attacked the USJ in an attempt to kill All Might. However, the majority of the League of Villains (except for Tomura, Kurogiri and Nomu) are defeated by Class 1-A. After All Might arrives, Nomu engages All Might in battle and is defeated. Tomura and Kurogiri try to finish what Nomu started but their attempt is thwarted by Izuku Midoriya and the timely arrival of the U.A. pro heroes. Both Tomura and Kurogiri are sucked into a Black Hole created by Thirteen (However, Kurogiri creates a portal back to their hideout, teleporting themselves out of harm's way). Thus, the League of Villains is defeated and the majority of the villains of the alliance (along with Nomu) are captured and detained by the police, leaving Tomura and Kurogiri as the only remnants of the League of Villains.

U.A. Sports Festival Arc
During the U.A. Sports Festival, Kurogiri sought out Hero Killer Stain, due to his notoriety. Kurogiri manages to find Stain and asks for a moment of his time, teleporting himself and Stain away. Stain meets with Tomura in order to test his evil.

Vs. Hero Killer Arc
Afterwards, Kurogiri teleports himself, Stain and Tomura to Hosu. While Stain goes off to finish his business, Tomura decides to humiliate the Hero Killer (as he got on his nerves) and sends three Nomus to attack Hosu. The Nomus fight the pro heroes and give them a hassle, as well as cause chaos and destruction along the way. By the time Izuku, Shoto and Tenya apprehend Stain, two of the three Nomus are restrained and arrested by the pro heroes and Police Force while the other Nomu is killed by Stain. Tomura, annoyed that nothing went his way, decides to head back to the League of Villains hideout. Kurogiri and Tomura leave Hosu.

End of Term Test Arc
After Stain's defeat, the media credits the League of Villains as an organization that harbors and carries out Stain's ideology. As a result, many newcomer villains who were inspired by Stain's ideology have sought out the League of Villains in order to join it, causing the League of Villains to gain spotlight and notoriety. Two villains, Dabi and Himiko Toga, also inspired by Stain's ideology, attempt to join the League of Villains so that they can be with the organization Stain was believed to be apart of, after being scouted by a broker (who decided to take advantage of the League of Villains' new notoriety) in order to earn more money. However, the meeting between Tomura and the two potential candidates does not go well. Kurogiri asks the broker to wait a few days for their reply regarding Dabi and Himiko's registration into the League of Villains.

School Trip Arc
Days after Dabi and Himiko Toga's visit to the League of Villains. Both Dabi and Himiko Toga are seen alongside two others stood on top of a mountain over looking the U.A. students camp site. When Dabi declares the heroes will fall, he mentions it's for the sake of the future. Once all members of the squad were gathered together, they launched a surprise against the camp while declaring themselves as part of the league.

The Vanguard Action Squad's attack on the training camp results in the injuries of twenty seven students and the capture of Katsuki Bakugo. However, the Vanguard Action Squad loses three members who are then arrested by the Police Force: Muscular, Moonfish and the gas masked villain. Despite these loses, the Vanguard Action Squad's success in capturing Katsuki Bakugo is a huge victory for the League of Villains as the capture has wavered society's faith and trust in Heroes.

Hideout Raid Arc
Inside their hideout, Tomura Shigaraki tries to convince Katsuki Bakugo to join them, but the latter refuses to as he has already being won over by All Might. Unbeknownst to them, the Heroes form a team to retake Katsuki Bakugo. The League of Villains are taken by surprise when All Might along with Gran Torino, Kamui Wood and Edge Shot single-handily apprehend them. Before All Might and Gran Torino can get the location of All For One out of Tomura, black liquid portals appear with dozens of Artificial Humans coming out in droves. The League of Villains are teleported away along with Katsuki to All For One's location. All Might defeats the Artificial Humans and chases after All For One while the rest of the Hideout Raid Team deals with the Artificial Humans. Meanwhile, Best Jeanist, Gang Orca, Mount Lady and Tiger have defeated Artificial Humans at a factory and manage to rescue Ragdoll whose Quirk has been stolen by All For One. All For One encounters Best Jeanist's team and defeats them along with destroying the factory.

The League of Villains teleport to where All For One is. All Might appears which causes him and All For One to engage in their final fight. All For One uses one of his Quirks to forcibly activate an unconscious Kurogiri's Quirk so that Tomura and his fellow villains can escape. As All For One continues battling All Might, the League of Villains try to apprehend Katsuki before leaving, but Katsuki defends himself against their attempts. Suddenly, Izuku, Tenya and Eijiro appear in the sky with Eijiro calling out to Katsuki. Katsuki grabs Eijiro's hand and the quad of U.A students begin their escape. Magne, Spinner and Mr. Compress attempt to stop them only to be intervened by Mount Lady. Gran Torino arrives and defeats Magne, Spinner and Mr. Compress, leaving only Himiko and Tomura the only active League members on the battlefield. The U.A students along with Katsuki manage to escape. Seeing that they are losing, All For One activates Magne's Quirk which causes the unconscious League of Villains to be forcibly pulled into Kurogiri's Warp Gate. Tomura along with Kurogiri and the other League of Villains successfully teleport away.

With Izuku's group and Tomura's League of Villains gone, All Might and All For One continue their viscous fight. All Might defeats All For One but at the cost of losing One For All for good.

Hero License Exam Arc
The League of Villains scatter in order to avoid detection by the Police Force. However, Tomura orders his fellow members to scout out for new recruits while they are scattered. Himiko infiltrates Shiketsu High and takes on the identity of a student named Camie. Using Camie's identity, Himiko participates in the Hero License Exam and manages to obtain a vial of Izuku's blood. After the exam, Himiko reports to Mr. Compress who is with Tomura at an unidentified place about her success. Dabi finds a group of thugs but sees that they are unworthy and burns them to a crisp. Twice manages to find and interesting villain named Overhaul and learns from Giran that Tomura wants the League of Villains to regroup once more.

Internship Arc
Twice brings Overhaul to meet with Tomura as a new prospective member. However, Overhaul finds Tomura's organizational skills along with his lack of coherent planning to be abysmal and instead offers to take the League of Villains under his wing. Magne refuses Overhaul and attacks him, only to be seemingly blown up by Overhaul's Quirk. Mr. Compress attempts to stop Overhaul but is intervened by one of Overhaul's men, causing overhaul to blow off Mr. Compress's arm. Furious, Tomura attacks in retaliation with his Quirk, but one of Overhaul's subordinates acts as a human shield and is disintegrated instead. Overhaul's subordinates come crashing in, but Overhaul ends their meeting before it escalates into a violent fight. Tomura orders his League of Villains to stand down. As he leaves with his Eight Precepts of Death, Overhaul tells Tomura to contact him after he has calmed down and to think about what his organization wants to achieve.

Eventually, Tomura contacts Overhaul again and the two villain leaders meet face to face again.