What if... All Might and AFO killed each other in Kamino?

In your universe, the eighth wielder of One For All and Symbol of Peace, All Might emerged victorious over his  old foe for the second time in Kamino. Unfortunately, things didn't turn out so well in this universe.

In Kamino, All Might actually hit AFO so hard with, United States of Smash, that he completely annihilated his head, thereby killing him once again. This time afterward, Gran Torino personally sees to it that his body is destroyed, thereby killing All For One, once in for all.

However, as All Might points to the camera and says, "Now... it's your turn." Suddenly, All Might collapses, his internal injuries are far too great, and his heart fails, ending the life of the Symbol Of Peace.

Deku hides in his room in a state of depression for days, until one night Deku has a dream and All Might's vestige visits him. All Might reaffirms his faith and love for his protege, assuring him that his death was no one's fault but All For One's (it's my theory that All Might living had a delaying result in Deku interacting with the vesitages). Later, Deku reveals the truth of why he was chosen to his mother, which just barely manages to convince her let him return to U.A.

Bakugo feels even worse then in canon, and is constantly snapping at everyone, and three days before the test he tells Deku they need to chat about his quirk. They both have it out, with Bakugo expressing his guilt that he believes he causes the death of All Might, and Deku expressing how he's felt about Bakugo's treatment of him all these years (as the added pain of All Might's death makes Deku more expressive). Deku briefly finds out he can raises his overall limit to 20% for brief amount of time. Ultimately the fight ends in a draw as Aizawa and Nezu (who stopped Aizawa from intervening at first, as the Principal knew the full story), and instead of house arrest, they are both given two days of detention, and Bakugo has to go therapy non debatable. Izuku also fills in Bakugo about the truth regarding OFA, and his own talk with All Might in the vesitage realm, assuring Bakugo he wasn't responsible.

The Provisional license Exam- ends more or less the same. Bakugo and Todoroki both still fail, I suppose the only real difference is that with 8% as his continuous limit, and 20% for emergencies he actually manages to land a blow on Gang Orca.

The Shie Hassaikai- Deku goes to Nighteye, at the behest of Gran Torino who is even more of an asshole then in canon, due to AM's death. Deku also has the dream of Yoichi, the same in canon after the classes's disastrous fight with Mirio  (Bakugo included this time) The raid occurs mostly the same as in canon, however in this reality Deku accidentally unlocks Fa-Jin while fighting Chisaki, defeats him with the aid of Eri, and later that night has a vision of Bruce, telling him about the specifics of the quirk. Nighteye survives the raid in this reality however it comes at the cost of losing his quirk and the use of his legs, finally accepting Deku as a worthy successor to All Might as he had defied his visions of death, and Togata is made aware of the truth, and actually retains his own quirk. Due to All Might's death, the PHSC *recommends,* that the Work Studies be allowed to continue.

School Festival Arc- is far more vital then in canon, as EVERYONE needs to blow off some steam after the death of All Might. After training with Nighteye during his work-study, Deku is capable of successfully utilizing both Fa-Jin and Air-Force as well as gaining far more experience is able to use 10-15% as his base limit, so he is take down Gentle Criminal and La Brava far easier in this reality. Deku and Ochaco get together around this time (as she was a massive help in his depression with All Might's death. And if Horikoshi's not doing it then fine, I'll damn well do it!)

Joint-Training Arc- Pretty much the same, Deku unlocks BlackWhip here, however he is actually able to stop it with Uraraka's aid.

Heroes Rising- Basically the same, only this time Deku awakens Danger Sense during his fight with Nine, for the lightning strikes.

Endeavor Agency Arc- Same as canon excpet, Deku goes to Nighteye and manages to master Danger Sense in addition to Blackwhip thereby unlocking half of the previous users' quirks.

World Heroes Mission- Nighteye would have taken All Might's place at Mission Control, while Togata and Deku would have been sent ahead with Bakugo, Todoroki, Centipeder, and Bubble Girl. Deku manages to overcome Flect Turn with the aid of his quirks and comes out victorious.

Paranomral Liberation War Arc- Mostly the same at first eventually Shigaraki wakes up at around 75%, activating Deacy and decimating Jaku City. Eventually however, Shigaraki is defeated by the combined efforts of Deku (as this Deku has multiple quirks at his disposal including Fa Jin), and his fellow heroes (though sadly Gran Torino perishes in the effort). However, Shigraki still attempts to steal One For All, and Deku is able to view his past the events that led to him becoming a villain just before he dies. Also since Deku, Bakugo, and Endeavor they are in *much* better shape this time around (not unscathed,  still pretty injured but not so much that it drastically impacts their fighting ability, for example Bakugo nor Endeavor got stabbed, and Deku only has a broken arm) they are able to help stand against Machia and the rest of the League managing to defeat them. 

Afterward, Toga is still at large, having managed to evade Ochaco though she eventually catches up with her. and while there are some Paranomral Liberation War members running free at the moment,  all lietunents were arrested such as Re-Destro, Geten, Trumpet, and Sketpic. Deku goes on to become the number one hero, and goes on to reform hero society along with his friends, to ensure another Tomura Shigaraki never rises.

There. That is my opinion on what would have happened had All Might and All For One killed each other in Kamino. I would love to hear your opinions on the matter, I just ask that you respect my opinions, just as I will respect yours.

(Personally, I believe due to All Might still being alive in canon, Deku would have been able to communicate with the vestiges more easily, due to the fact he was the only living OFA inheritor. As due to the embers still residing in All Might at the time, it created a kind of delay for Deku to speak with the vestiges.)

What if All Might and All For One killed each other in Kamino