Lithnox
I think it depends on the ages of them. If he’s Momo’s age I think you could make a cute couple out of them in middle school and carry it over. If you have him be the same age as the big three or one year under them I suggest Nejire. I really like the idea of him being in between izuku and Togata it would make an interesting dynamic. You could even have him skip some grades because he now has the hacks with the sharing on that makes it so you have the ability to learn things easier and a near ediactic memory.