Everyone knows that there is a chance Deku was born quirkless. I say quirkless as there are theories that his quirk was probably stolen as his doctor who diagnosed him as quirkless looks like the doctor who works for All For One. Anyways, Deku gain One For All from All Might and had multiple quirks at his disposal. But now, you are probably wondering what kinds of quirks he could of have if he had one.
Both of Deku's parents had quirks, which would make Deku a rare case of being quirkless. His father has an unnamed fire breathe quirk while Deku's mother can attract small objects. By using this data, I thought of quirks Deku may of have.
Heat Wave
Heat wave would give Deku the ability to heat up the air around him to high temperatures. However, it is possible that Deku wouldn't be resistant to the heat. I say possibly because I don't know much about his father. As if his father was resistant to heat, Deku could use his quirk without burning himself out.
Weaknesses:
Burning himself out - A 50/50 chance, even if his father has fire resistance or not.
Telekinesis
Pyrokinesis
Float
Flight
Enhanced Fire Breathe
Deku could have a more powerful fire breathe quirk. Where the flames may be way hotter. Since I don't know much of how Deku's father quirk works, I couldn't really describe much here.
Object Magnet
It could give Deku the chance to turn any object into a magnet just by touching it. That object would be able to attract any objects for a duration of time. Another cool mutation from his mother's quirk.