WARNING: The following contains spoilers for My Hero Academia Chapter #326, "Who Are You Really?” by Kohei Horikoshi, Caleb Cook and John Hunt, available now in English from Viz Media.
Chapter #326 of My Hero Academia takes a break from all the chaos at the UA High shelter and catches up with All Might. As he struggles to keep up with Deku’s endeavors, he starts to question his own heroic conviction. Since he is unable to protect the disciple he cares for so much, All Might feels as if he has no reason to continue being a Hero. As All Might sulks in his sorrow, Hero Killer Stain appears, and reminds him why he will always be perceived as the symbol of peace. Stain’s appearance sparks the question: is he really fighting for a true Hero society, or is he simply an All Might mega fan?
When Stain calls out the weakened All Might for being a fraud, he is actually referring to his heroic conviction. Stain reveals at the end that he is aware of how All Might lost his abilities, but that doesn’t mean the Hero himself ceased to exist. It could be safe to assume Stain has been waiting around the All Might statue for this very moment. He hasn’t lost hope in the symbolism of All Might, reminding him how the embers of rebirth shine brightly within his students.
Stain acknowledging the students of Class 1-A as the embodiments of All Might’s will is a clear sign that he’s the vigilante My Hero Academia needs, but might not want. He's looking out for the greater good of true Heroes, but at the cost of murder. Stain has killed 40 Heroes, and even invites All Might to be the one to take him down. He could almost be perceived as a double agent like Hawks and Lady Nagant -- the only difference is that he doesn’t have the support of the Public Safety Commission. This moment could possibly be confirming that Stain doesn’t plan on killing anyone from Class 1-A, though this isn't certain.
The information Stain provides at the end of Chapter #326 is a clear indication he still believes All Might is not done being a Hero. A Hero society fails if the civilians cannot trust their protectors, and Stain has granted All Might an opportunity to rekindle hope in the eyes of society. The information will kickstart the next arc of My Hero Academia, and might even tease a Stain/Hero team-up. This could also be teasing an opportunity for Lady Nagant to reappear and further validate some of the info provided by Stain.
The interaction between All Might and Stain makes it feel like their roles have switched. All Might sulking like someone without hope has been the precursor of Heroes defecting to villains or straight out quitting. The whole situation could even be described as Stain acting as the Hero All Might needs at this moment, during all the chaos. Stain doesn’t need retribution for all the evil he’s done, he just needs All Might to return.
All Might receiving praise and getting some sense knocked into him seems unorthodox, but the current situation in My Hero Academia doesn’t necessarily call for straightforward events. Deku running amuck, civilians turning on Heroes, and Stain giving Hero pep talks to the former #1 Pro Hero -- what could be next? It’s good to see the Heroes receiving aid from unexpected avenues. All Might will need to reconsider many things, and the next time he meets Deku could potentially be his last. His purpose is to lead by example, and what could be more Heroic than allowing your body to move on its own as a sacrifice to protect the embodiments of your will?