I had a conversation with a commenter MrTicklesMMM over a year ago about how All for One seemed like the type to pull an Aizen. We had the exact same thought about the Uraraka construction company. It's been a while so I might not remember perfectly but here are some other ideas for AFO responsible for every evil ever:
-Katsuki was a very kind boy until AFO used a quirk to make him hate Izuku.
-AFO has been quietly stealing cookies Rikido Sato's bakery for years.
-AFO swapped out Denki Kaminari's quirk for LOLs and gave him one that fries his brain when he uses it.
-With subliminal messaging, AFO turned Minoru Mineta into a perver.
-He cyberbullied Momo to destroy her confidence.
-He separated Eijiro Kirishima from his twin brother, Tetsutetsu, at birth so that they were raised by different families.
-AFO shot Seroās uncle, who then told Sero that with great power comes great responsibility. This was specifically a Spiderman tribute. He did it to Daigoro Banjo too, because he also seemed to have sorta weblike powers.
-AFO mutilated Mezo Shojiās face.
-Somehow, he gave Koda Koji his bug phobia.
-He dumped estrogen into the Asui family water supply resulting in Tsuyu turning female (yeah, that's a thing that happens to frogs.) She's the only one who doesn't care.
-Yuga Aoyoma wasnāt born quirkless. AFO stole Yugaās original quirk, Glitter, partly to use him as a traitor later but mostly because he wanted it.
-AFO swapped Dark Shadow and Fumikage Tokoyami: their personalities are at odds because the quirk was originally the human and vice versa. Fumikage realizes that he was always destined for the darkness and the now ironically named Dark Shadow is a being of the light.
-Heās the one who sent Gigantomachia after Minaās friends.
-AFO was behind Enji and Rei's quirk marriage. When Shouto points out that this is technically a good thing from his perspective because he wouldnāt exist otherwise, AFO says that he also inflicted Dabi upon the world. Shouto sighs and nods.
-He's the reason Toru Hagakure canāt turn her power off. He obtained a quirk a long time ago that can alter the classification of other quirks. Toruās ability was supposed to be an at will power, but he made it a mutant quirk.
-AFO was behind the music industry raising the price of online songs. He hoped to convince more people to pirate music. Kyouka Jiro nearly claws his eyes out.
-He gave fake info about Tensei to Stain, āprovingā that Tensei is a corrupt hero. He hoped Tenya would become a murderer to take revenge and it almost worked.
-Ojiro Mashirao asks what AFO did to him, and AFO is startled. He admits he never even noticed Ojiro is in Class 1-A. Ojiro is much more upset than if AFO had ruined his life.
-AFO hired Muscular to eliminate the Water Hose duo.
-The Sludge Villain only went around committing crimes because AFO promised to swap out his awful quirk if he came up with enough money.
-AFO convinced Re-Destro to follow in the footsteps of his ancestor by saying he personally knew Destro and his last wish had been for his descendants to carry on his mission. Except with even more violence.
-For Dabi, the same except Dabi is upset AFO caused Shouto to exist.
-AFO cyberbullied Spinner as practice for Momo.
-He killed the real Twice and swapping him with a clone for LOLs.
-He tricked Compress into thinking his ancestor was more about randomly killing people and less about wealth redistribution.
-AFO told Toga's parents they should starve her of blood and that would cure her craving and cause her to switch over to craving fruit juice.
P.S. It's all a lie. AFO did not do most of those things, he just claims credit for everything that goes wrong ever.