Aizawa refuses to let his Problem Child travel back in time alone, even to fix a future where All for One was the victor. They go back with a plan that's more of a list, spend a year technically missing, and become rather effective vigilantes that fix some rather serious problems. And then it's time to be found, which seems to primarily result in lots of support and many hugs. Neither Izuku or Aizawa complain very much.

Every single school had one: someone at the top of the food chain. An acme. Someone who could do things under a teacher's nose, escape consequences, and terrify other people. Someone who looked down on everyone else like they were prey. An apex predator. And Izuku couldn't count on teachers and adults to protect anyone. Even a hero school wasn't safe from the phenomena. When Izuku gets to Yuuei, he's determined to find out who it is and ensure they can't hurt him or his new friends. ...and accidentally, in the process, becomes the apex predator (though he is mostly unaware of this, and uses it for good. But still, people are terrified of him.) (Or, a snowball chain of events wherein Izuku's paranoia leads to 1A becoming a family, everyone in school being in debt to him, Aizawa adopting everyone in his sight and slowly growing closer to committing acts of arson, the League gaining redemption and working with the resident Apex Predator to combat the Hero Commission whilst gaining technically legal identities, and Hawks finding a family. Hurt people help other hurt people, and they're all doing their best. Some laws may or may not be broken in the process.)

Shouta’s plan had been ill-defined and desperate from the start, but he figures the important shit boiled down to, “Change as little as possible, make sure Midoriya doesn’t get himself killed, and stock up on lychee jelly pouches because that flavor got discontinued three years from now.” Keeping it simple’s always better, and he’s normally good at improvising. Somewhere along the way, he must’ve fucked up since now he has: A quirkless problem child hanging off of his every word His best friend going through a sexuality crisis thanks to said problem child’s mom His other best friend clinging to him like a security blanket Some two-bit mob boss threatening him with bouquets of daffodils To wring the number one hero’s fucking neck for not telling him anything useful before sending him decades into the past All he did was walk Izuku Midoriya home. It wasn’t meant to turn into whatever mess this is.