The author ruined this character.
It would have been better story telling if Almight had noticed the courageousness of izuku when izuku jumped in to save bakugo like in the original series. It is then revealed that almight had already handed his qurik (handing over his power to someone else).
As a result almight would feel guilty upon his earlier words to izuku stating that he can't be a hero without a quirk and as a result still trains izuku just like he did in the original series when he wanted him strong enough before eating his hair.
Fast foward izuku enlists in the police Corp. We see how the training there is different, however there is a special unit that is trying to get some of its trainees to also work along side heroes. As a result the school has a partnership with the police program allowing its top rankers to enlist in the Hero school for assistance. Instead of being in class A, izuku would be enlisted to assist Mei since it's been observed that deku keeps himself in shape and knows alot about quirks and tech (which was why izuku would be respected in such high regard in the police cadet even though he is quirkless). Basically izuku will be in 1C instead of 1A.
Even though izuku's number 1 idol is still almight, the type of hero he wants to become based on what he can achieve is Erasure head. (It's because of the fact that erasure head is just goated at fighting even though his quirk doesn't augment his skills in any way)
Izuku's main rival would still be bakugo but his smaller immediate rivals long the way would be SHINSO'S whom would also be in 1C and Neito Monoma from 1B. Shinso trains under Erasure head and Snipe, Sonoma trains under Sir Nighteye and Gun Head, while izuku trains under Erasure head, Sir Nighteye and Grand Torino.
Izuku would learn who the person is whom almight gave his power too and as a result work hard to be strong enough to protect him. As a result grand torino would still have an interest in izuku helping him train
Izuku would still learn Shoot style from watching Ida, and he would still try replicating almight punches with Tech (light brass knuckles for his fists and steel toe boots) that augments his leg and fist strikes temporarily and only when he charges it up (though not nearly as much power as he would with one for all).
Izuku still participates in the UA festival which bumps him up to being in class 1B based on his overall performance. He still wins the race match and loses to todoroki in the last 1v1 match, but his fighing style is different from the original series with him using what Erasure head taught him along with using mei's equipment such as smoke bombs, land mines, foam extinguishers, etc which still forces todoroki to use his flame and ice.
The major story events remain the same with the exception of izuku's fighting style in EOS being:
Erasure-heads hand to hand combat style and use of weaponary and binding.cloths (no Erasure obviously)
Still having shoot style
Peak Human athleticism, Peak Human Strength and Peak Human Movement speed
Increasing his speed and hits in burst upon using tech created by Mei. Also having smoke bombs, flash grenades, and binding cloth that helps him immobolize and subdue opponents while also swinging him from place to place like spiderman lol. He would also have foam extinguishers to put out fires fast against explosion/flame based opponents. And lastly a solar saber that gathers the heat around it to create a light Saber. The hotter the area the more powerful the cutting of the saber.
Natural super human reflexes and prediction (Not a Qurik) that he honed for years by studying heroes and villians and further training with Sir nighteye.
The rest of the story can remain the same with the exceptions of Eri restoring Erasure-head back to normal (no more missing leg and eye), and to eventually heal almights injury thus almight is back to prime shape (no one for all). Eri restored endeavor back to normal so that he can resume his title as number 1 hero. Almight is still revered forever as being number 1 even though he lost his quirk since he is now back in fighting form and now has a gauntlets and shoes to augment his already high strength and speed (even more so when his gauntlets and shoes form an entire exoskeleton suit on almight resulting in him replicating the speed and power he once had when having one for all (though its still limited in its full usage per day). Izuku in the earlier parts would still feel like its his duty to protect the future user of one for all and as a result he still takes the burden onto himself as being the one up NEXT (as in person meant to defeat shigaraki and all for one) when almight lost his Embers fighting all for one. It's revealed that the person whom almight gave his qurik to is a young kid (much younger than deku) that already has a quirk that allows him to only heal his own injuries. Almight did this to ensure that the future one for all user would not overly hurt himself or kill himself with the power of stacking associated with the one for all. In other words this dude can serve as the longest lasting one for all user. The last major fight consists of these major players that all got power buffs and were healed by eri in the end:
Izuku (Hero name Valiant): moveset as stated earlier above
Aizawa: (Hero name Erasure Head): Has the same abilities and techniques from the original show with the exception of now having Dual Katanas made of incredible metal thats sharp that also retracts, explosive kunais, shuriken that when thrown creates heavy concussive blunt force and vibrations through the body, upgraded binding cloth that stuns the opponent when aizawa binds then and clicks a button on his colar.
Mirio (Hero name Lemillion): All abilities the same
Enji Todoroki (Hero name Endeavor): All abilities the same
Toshinori Yagi (Hero name All Might): Was restored back to his physical prime yet he no longer has one for all. To make up for this in the final war and moving foward he is given power boots and power glove gauntlets that augment his already high natural speed and power. To enhance these things further the gauntlet and boots expand creating and exo-skeleton creating a power suit that allows all might to replicate the strength he once had when using one for all (though much weaker and there is a time limit per day on how long he can use the suit like this due to over heating)
Shoto Todoroki (Hero name Shoto): All abilities the same
Bakugo (Hero name DynaMight): All abilities the same
At the end of the story civilians and heroes look up to izuku (valiant) as one of the greatest heroes to ever live due to the fact that he became a hero without a quirk "A hero that never needed a Quirk to be ONE"