kendo stan blog

We can see in chapter 407 that All For One had the holes in his hand that allow him to use his quirk since the moment of birth. We also see that he doesn’t actually care for his brother as a person but rather as a possession. I think it’s fair to assume that if he had a child it wouldn’t be out of love or desire for a family. So maybe he got with Inko (probably just picked a woman at random or maybe she seemed easy to manipulate given how emotional she is) under a false identity in hopes of producing a child that would inherit his quirk so he could use them as a new vessel. (He also could have chosen Inko in hopes that their quirks would combine and allow him to use AFO from a distance). When Izuku was born with no sign of All for One (no hole in the hands) he simply left them under the guise of working overseas and moved on to new plans. He would’ve then found the Shimuras and passed Decay onto Tenko (who would’ve been around 5 years old when Izuku was born, young enough that it could pass off as a late manifestation) and taken him in to raise as his new vessel. This would explain why Izuku has seemingly no reaction to the memories he’s shown within One For All. And All for One, if he really doesn’t care about his child, is just saving this information for the most opportune time to reveal it. Maybe to throw Izuku off his game while fighting Shigaraki. In addition, the reason All for One didn’t kill the UA students at Kamino (despite having Search and possibly another quirk that would make him aware of them) would be a superficial attachment to Izuku, viewing him as just as much a possession as his brother, rather than any actual love for him.