The “All for One is Izuku’s father” theory is both interesting and hilarious because any time I think about it, I just imagine Toshinori finding out and having a “I love this child with every fiber of my being and he has my complete trust but how the fuck did I manage to choose the one (1) child of my arch-nemesis as a successor” moment.
There’s also this
All for One: That’s my son
Toshinori, who has been Izuku’s father figure for years by now: I’ve already won this game and I didn’t even know I was playing
All for One holding newborn Izuku while forgetting to turn off his quirk stealing bullshit: Ah…I’ll fix that later
Ok there are a lot of things that I love about All Might, but one of them is the fact that when you remove him from the context of hero work, he’s just. So bad at doing things. Like, yeah, he’s the world’s best hero, and damn earned that title, but as a teacher? A civilian??? He just has no fuckin idea what to do. He’s good at his job and his job is Not That, please be nice to him