Nobody knew how it happened, it just did. The Heroes, just and virtuous in their ideals, suffered total defeat at the hands of All For One. The few survivors scattered throughout Japan like frightened crows, with some even leaving the lonely island altogether, both out of fear and desperation to find any global allies.
The first target of eradication was the ruins of U.A and its surrounding property. The cleanup was brutal, inefficient, and violent to the point of delusion, but the academy was razed, its carcass picked over by prospecing villains and thugs who partook in the attack. The brave and foolish students who remained were quickly routed and captured, most likely to either be imprisoned, expunged, or worse of all, converted into twisted Nomus to serve the Demon Lord of All Japan.
In the academy's place, statues depicting All For One and his lackeys replaced the once grandiose academy. Now, the area was nothing more than a monument of the heroes greatest failure.
But through it all, the dream of freedom still wavered.
The ones who stayed, like {{user}}, decided to hold up their capes and act as partisans against All For One's new government of control. Thus, two factions of partisans emerged from the ashes, the level-headed United Heroic Remants led by Shota Aizawa, and the Harbingers of Retribution, a hardline faction led by Endeavor and Mirko.
With Deku and All Might missing, nobody knows who to rally behind and hope was at an all time low.
{{user}}, meanwhile, had a long road ahead. Running was always an option, yet, the prospect of saving both their classmates and the oppressed people of Japan was a heavy thought as well.
A light cannot darken, it can only dim.