Some context for this AU
Izuku, Ochaco, Denki, Shoto and Hitoshi are vilains and at the same time Himiko, Mustard, Jin, Shuichi and Chizome are heroes or citizens.
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Himiko Toga is an apprentice hero, she studies at Yuei in the class 1A. When she was young she had a good quirk counsellor who really help her understanding her quirk and her natural need of blood. The result is she isn't a psycho (at least not more than the craziness of every single teen) she is just very excited and playful. Also she is in a foster family because her parents are crap.
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Mustard is just a normal citizen with a lovely family and a lovely life. He just deserved it.
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Jin Bubaigawara is a pro hero who studied at Ketsubutsu. He is a good friend with Hawks and Miruko. He likes help the young apprentices so he is a frequent guest at hero schools.
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Shuichi Iguchi was a regular citizen until he discovered Stendhal's ideology. This change in his life help him find a new motivation and goal in his life. For applicate Stendhal's ideas he decided to become a policeman. He is noticed by Sansa Tamakawa who give him his job in the police.
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Chizome Akaguro aka Stendhal is a vigilant famous for his ideology. He thinks the role of vilains is to be a challenge for heroes and societies for push them into being the best version of themselves. He despises vilains without objectives or who just want chaos, power and money. A true vilain should have a will for change the world, all the other are parasites who block the progress, so he eliminates them. He is searched for the murders of several traffickers and dealers.
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Izuku Midoriya aka Izuku Shigaraki is the son of AFO and Inko Midoriya and the little brother of Tomura Shigaraki. Yes Inko knows her husband and sons are vilains and yes she is okay with it, the woman is a marvelous mom but she has a lot of chaotic energy. At first Izuku was raised regularly and was friend with Katsuki. But when he was declared quirkless all his friends turn their back to him and Katsuki started to bully him. For sum up Izuku decided to go ape shit for his father biggest joy and because the boy is a smart bean he becames a terrifying vilain with just his brain and a gun. He changes his last name so his mother doesn't have troubles because of him. AFO was a little worried for his son (he should be worried for the world) so he gives him a quirk. It isn't a powerful thing because Izuku don't need one, it's called Checkpoint and it allows Izuku to save a location and teleports himself and what he is touching at this location. He can only save three locations max, a new location deletes the oldest location. He is the co-leader of the league of vilains with Tomura, the two have a playful relationship and like being in competition for know who is the best vilains boss.
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Ochaco Uraraka had the habit of doing illicit jobs for helping her family. She is less naive and innocent than canon Ochaco, she is more bitter for the state of the society she lives in. AFO pays her for being the Yuei's traitor. She doesn't particularly enjoy see her classmates hurted but after meeting Izuku she genuinely believes he and his peoples can make a difference in the world. Also she certainly enjoys the checks AFO gives her and seeing pro heroes being fooled by a teen girl. She has a big crush on Himiko.
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Denki Kaminari aka Medusa, illegitimate son of an American business man and an accident for his mother. At his birth the hospital noticed the bad health of his mother because of her addictions so his dad was forced to take responsibilities. He doesn't really know his dad who send him live with his aunt in Chigaco. When he was six his mother was allowed out of the hospital and his dad happily send him back in Japan. His mother continued alcohol and frequented differents men until she stayed with his step-dad who was a drug dealer. The man make him drop out school at ten so Denki can work for him. He learned a lot about the organization of traffic, stealing, dealing and later dispose of a corpse. Since his quirk is very useful his step-dad makes him work for him then selled his services for others. With time Denki get rid of the jerk and work independently. He signs a contract with AFO for him to keep an eye on his sons and the league project and also protect them if necessary.
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Shoto Todoroki aka Tosho, when Toya ran away from his father after he almost died in the flames he takes Shoto with him. Times been hard but they survived, escaped heroes and police and grew up pretty close even if they're two dumbass. They end up in the vilains side with the pseudonyms of Dabi and Tosho. Shoto still have his scar which he hides with an eyepatch, he dyes his hair in black and only use his ice but it isn't because he has a problem with his fire it's for helping hide his identity (his quirk his very remarkable). The brothers joins the League of Vilains and Shoto find the green bean very nice.
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The life of Hitoshi Shinsou stays the same except after the sport festival. Before Aizawa can propose him a special training for becoming a hero Ochaco and Izuku meet him and help him accepting his quirk and show him how he shouldn't be a hero just because he is bitter of the world. Short way they convince him of becoming a vilain and being the second traitor with Ochaco. When Aizawa socially awkward approachs him it's was too late, he already found a group of people who support and accept him.
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Other things:
-the vilains aren't big psycho or what, just a punch of dumbass
-AFO is a son of bitch who is bad at parenting, Tomura and Izuku are only stable because of Inko and Kurogiri
-Tomura was quirkless and AFO gives him Decay for provoke the accident but nobody knows
-Denki always wears ether his vilain's mask or a surgical mask because he has a kind of trauma about some scar on his face
-Shoto is still social awkward but in a chaotic way
-Inko living her life watching peacefully her sons destroys Hosu at TV
-Ochaco is a bitch with Katsuki because she knows he was been a dick with Izuku
-Tomura and Izuku challenge themselves for know who had the best plans. Tomura made the USJ's and Izuku made the Summer Camp's plan
-Izuku kinda likes All Might but isn't the hardcore fanboy Canon Izuku is
-I use Medusa and Tosho for designated Denki and Shoto in the texts because they don't use their real names
-I use italic for Denki's dialogue because he has a voice modulator in his costum's mask. Technically when he doesn't have it he use JSL or ESL