So I was thinking with the recent chapters confirming that Deku might be slightly influenced by his quirk factor, and AFO quirk/soul explanation is if AFO is already within OFA quirk via the quirk he gave his little brother. You can say that it’s probably not considering that quirk he gave him probably wasn’t originally AFO, but than by that logic his lil bro may have been able to see whoever the owner of that quirk was. However I think thematically it would work that AFO is already somewhat of a vestige that Deku just hasn’t interacted with yet. I don’t think AFO would try to take over his body, not that he could, but I believe that he could use it as a way to torment Deku.

Tbh there are a lot of holes in this, but after seeing AFO make Nagant explode, and you could see him inside of her in the second to last panel before hawks intervenes. I would say it’s safe to asssume a remnant of AFO is already inside of Deku.