The following content contains spoilers from My Hero Academia Season 6, episode 25. Chizome Akaguro started out with all the honorable intent in the world but like numerous others, found many flaws within the system that secures Hero Society's success. In contrast to Danjuro Tobita, Chikara Yotsubashi, and several others with disappointed heroic hearts, Chizome didn't subsequently turn to a life of crime but took up vigilantism instead, with only Villains on his radar.
Somewhere along the way, Stain grew to hate Heroes as well, deeming them false idols undeserving of their status, and took it upon himself to assassinate forty Heroes (and counting?) He has since gained a wide following, surprisingly not Villain-only supporters, which seems quite absurd! However, a closer analysis of Chizome's objectives, especially in light of Season 6, leaves many questioning the Hero Killer's Villain title. Sure, he has killed people, but so has the Hero Public Safety Commission; all for the sake of the perceived greater good.
The Inspirational Stain
Despite what people want to believe about the Hero Killer, statistics are undeniable evidence of his influence, as every city visited by Stain 'suffered' from reduced crime rates. Shoto Todoroki may have described him as an "anachronistic fundamentalist;" however if one were to quote Stain out of context and assess his statements as-is, evil and sinister are unlikely to be the first words to come to mind.
"It's no use trying to reform for appearance's sake. A person's essence does not change so easily."
"No matter what you want to accomplish, it is necessary to have conviction and desire."
"Reflect on yourself and save others. Don't use your powers for yourself. Being taken in by the hatred before you and trying to fulfill your own desires... That's the furthest from what a hero could be."
The latter quote forms part of the lecture Stain gives Tenya Iida in Season 2, episode 16, after cornering the youngster in a terrifyingly vulnerable situation. By this time, most viewers have already fallen prey to the suggestion that Stain is the Big Bad, so his motivational speech comes across as somewhat delusional, taunting, and manipulative. Coupled with the blood-crazed nature of his Quirk, and the perfect recipe for prejudice materializes.
A great deal has happened since Stain's arrest, and many viewers may have forgotten that the Hero Killer actually saves Deku from being abducted by a rogue Nomu in Season 2, episode 17, risking his own freedom in the process. Whether Stain was still planning on murdering Deku afterward is debatable; however, if he could break through his restraints to annihilate All For One's monstrous minion, Stain could have just as easily fled to freedom while everyone else was distracted.
Apart from his warped sense of justice, Chizome seems to have the meaning of life all worked out, which is quite a flex by anyone's standards. Now that Season 6 has drawn to a close and many Heroes have shown their true nature and Stain's declarations sound eerily accurate; hindsight is 20-20, after all.
"This society overgrown with fake heroes...and the criminals who wave their power around idly...should all be purged... This is all to create a just society."
"Too many acts like Heroes but are only money-worshippers."
"The soul of a Hero exists for the sake of others."
And while mass murder is unquestionably overkill, Stain's sentiments about weeding out the bad eggs make complete sense (and the label of Hero or Villain shouldn't affect these evaluations.) It wouldn't be a surprise if Eric Kripke confesses to being a Stain fan, as the whole plot of The Boys essentially revolves around the same sentiments.
The Hateful Hero Killer
Chizome clearly doesn't agree with the League of Villains principles, which generally align more with mindless destruction than the "virtuous" pursuit of Hero eradication. The only things Stain and Shigaraki could agree upon is that the current state of affairs with Hero Society is undesirable and that carnage is a plausible solution. Things might've turned out differently for the Hero Killer if Stain had met up with Re-Destro and the Paranormal Liberation Front instead, potentially without a ticket to Tartarus included in the package.
While it's easy to sing Stain's praises, despite how arguably virtuous his mission may be, the Hero Killer evidently became seduced by success (ironic, isn't it?) and started targeting all Heroes, regardless if they met his criteria for being worthy of carrying that title. Hating on Endeavor is one thing, but Ingenium, Native, The Crawler, and countless others have no red in their ledgers and are undeserving of such harsh and fatal criticism. However, Stain became drunk with power and began attacking Heroes without reason, and therefore has no right to look down on the likes of Shigaraki and the League. And yet, as soon as things get 'real' and his dream comes to light as Hero Society crumbles, Stain immediately defies All For One and essentially becomes an accomplice to the Heroes, so what changed?
"Is That Blasphemy Against A Hero?"
Since escaping from Tartarus, Stain has been singing a new tune, surprisingly giving Deku and Bakugo some competition in the #1 All Might Fan department. Chizome describes Kamino as "the sacred ground of a hero," and is unconcerned with All Might's scrawny physique but appalled by his self-loathing hopelessness, which he considers to be blasphemous. He goes on to call All Might a "fake" and an imposter, but makes no effort to kill him; doesn't Stain hate false Heroes, and wish to eradicate them all from the Earth?
Perhaps his time in the big house has enlightened Stain in the error of his ways, urging him to seek retribution at the first opportunity. Alternatively, his inherent heroic traits could have kicked in during the turmoil, and the reality of a world overrun with bloodthirsty, lawless Villains suddenly hit home. In the case of "be careful what you wish for," perhaps Stain sees the fruits of his labor, which are all rotten to the core. Chizome is a smart man, and encouraging All Might to believe in himself once again is a silent nod to the fact that Heroes should be celebrated because, well, look what happens when they are not. And in Stain's case, sometimes it's best to go one step forward and three steps back; he started out as an aspiring Hero, after all.