Ok starting off with a less simple idea to start
I know this has been done a billion times over in every fandom but hear me out! Also this is one of my more thought out ideas, a lot of them will probably be a lot shorter than this beast!
Everyone, both quirkless and not, has wings. The size*, color and type of wing vary person to person, but usually they are a natural color for that wing type, so if someone has raven wings they would likely be an iridescent black. People who have a species with more emphasis on the tail also have said tail, like peacocks. They may also take some of the behaviors of their species.
(*Note: the size of the wings are usually proportional to the person’s body based on the species proportions, wing size doesn’t say much about a person personality wise)
Dispite having wings, not everyone can actually fly. In fact, it is extremely rare for someone to be able to fly at all, but it’s less rare for someone to be able to glide.
Heroes are much more likely to be able to glide but only a very small handful can actually fly.
It is also an unspoken rule in this winged society that you never ever go for someone’s wings in a fight. Even most villains will abide by this rule, and even if they don’t, a hero will never retaliate by stopping to that level. Someone loosing their wing is extremely uncommon and is a tragedy and a horror, like loosing a limb would be (but surprisingly wings are more rare to see amputated or lost). Being charged with purposely damaging someone’s wing is a high offense with a high punishment.
This now brings us to the character list! I do not have every character here, only the ones I came up with so far, but more may be added in the future!!
Aizawa has dark-brown-almost-black barn owl wings. His right wing, however, was torn off at the bend due to him having been kidnapped when he was 24 or so by a group of extremists who wanted to get rid of people who’s wings were from that of a death omen. He wears a prosthetic to even out the weight (and lessen the pitying stares), but it gets very uncomfortable so he only wears it while actively working or teaching (he takes it off in the staff room and when he has breaks). He used to be able to glide quite well and even gain a little bit of height but he can’t anymore. The students are unaware of his prosthetic. His wingspan from tip to tip with the prosthetic on is just under 17’ 5”. His natural wingspan is just over 13’ 1” because he lacks half of his right wing. It is also worth mentioning that he never fully extends his wings, barely extends them at all actually
Present Mic has white sulphur-created cockatoo wings with dyed yellow primaries. He can glide, but not in costume because his outfit is too heavy with all the leather and the speaker. His wingspan is about 12’ 2”
All might has yellow golden eagle wings, though his primaries are dyed red and his secondaries dyed blue. In his muscle form he can fly fully but in his true form, his wings aren’t cared for well enough to achieve flight, though it is likely he would be able too if he preened more often. His wingspan is just over 15’ 2” in both forms
Midoriya has olive green broad-tailed hummingbird wings. He is predicted to be able to hover a little bit but his wings aren’t strong enough yet, and are still (comparatively) quite small, though they won’t be too big when fully grown either. When he is moving or thinking, his wings are always buzzing and it is very odd to see them tucked. His wingspan is 7’ 11” but is predicted to get to 8’ 1.5”
Bakugo has white mute swan wings. He can glide but he has a hard time keeping his balance so he prefers to just propel himself through the air with his explosions. He is likely to get better balance once his wings are full grown. It is currently unclear if he will be able to fully fly, though it is unlikely. His wingspan is 9’ 11” but is predicted to get to 10’ 3”
Todoroki has a rare mutation which gives him a different type of wing on each side of his body, probably due to his quirk. His fire side has a reddish brown cactus wren wing, and his ice side has a light grey Arctic tern wing. Due to the difference in wings, he will very likely never be able to fly or glide. His wingspan is 9’ 6”, with his tern wing being 5’ 8” and his wren wing being 3’ 10”. His predicted wingspan is 9’ 9”
Iida has gray almost blue perigrine falcon wings. He can glide well and if he is high enough, can even do the high speed dive and catch himself, though he falls a few extra feet and it takes a second to fully catch. His wings are mostly full grown, his wingspan being 11’ 7” with only about another inch to grow
I might develop this more later but for now this is what I have!