After the most recent chapter, do you still believe Shigaraki can have redemption?

Short answer: yes. 

Long answer: the circumstances of his abuse haven't changed simply because he's now stronger. 

The fact that he accepted to inherit Afo’s quirk doesn’t take away his redeemability from him, because the entire point of Afo’s abuse was to mould Shigaraki into the perfect puppet he wanted Tenko to be. 

Let’s take a step back for a second. Remember this scene?

This is Shigaraki literally parroting the words Afo convinced him of. 

He says these things because he believes in them, but that doesn’t make them true. For one, because he’s an unreliable narrator. 

For those of you who never studied 20th century literature, an unreliable narrator is a narrator whose credibility is compromised. A good portion of 20th century fiction was dedicated to showing how the main character status often doesn’t equal credibility. For example, in the novel Zeno’s conscience (1923) by Italo Svevo, the MC is a neurotic nicotine addict who writes a memoir under the sugestion of his therapist, but his narration is fragmentary, interspersed with lies, because he doesn’t trust his doctor and he has lots of gaps in memories and often contradicts himself. So by the end of the novel, the reader is confused because we aren’t given a solid clue of what was true and what was false. We simply were offered Zeno’s point of view. 

But unreliable narrators don’t have to be that drastic. It can simply be someone who reads reality a certain way because they’ve been conditioned to read it that way. By virtue of being a character in a story, your point of view is limited and it encompasses just your experiences. 

To quote from wikipedia, one of the ways in which an unreliable narrator can be presented is through the trope of the madman: 

I’m not going to armchair diagnose Shigaraki with a mental health issue, but the very baseline reading of his character involves you to recognize he’s a seriously traumatized kid who was forced to adopt a series of coping methods to deal with the unaddressed grief from losing his family. This simply because Afo never brought him to a therapist, but rather had an interest in letting Shigaraki’s trauma remain as vivid and as crippling as possible, because it made moulding him into his obedient puppet easier. 

Afo literally admits on screen that he’s using Shigaraki’s trauma and his overwhelming guilt to keep him docile.

Why am I making this digression? Because when Shigaraki says “I killed dad because I wanted to,” that’s not Shigaraki acknowledging a truth. It’s Shigaraki narration showing sings of his lack of credibility. 

Afo forged for him a narrative in which Tenko was a bloodthirsty monster with a monstrous power lurking underneath his skin, waiting for release. But quirks don’t work that way. They’re not gods that require blood sacrifices to be kept docile. Quirks are just body functions. You don’t need to “feed” them anything. 

This sort of narrative, however, is very convenient for Afo because it makes Tenko a slave to his own uncontrollable power. If Tenko cannot control his quirk’s “hunger”, it goes without saying that he lives with the constant fear of killing people he’s close with. Of repeating the bloodbath. And of course little Tenko doesn’t want that.  

Are you starting to see it? This is how Afo kept Tenko himself docile. Who would want to stay close to a kid that’s that dangerous aside from Afo himself? Stay with me, Afo told him, because no one else in the society of heroes is gonna accept you for the bloodthirsty monster that you are. Only I am kind enough to love you even if you’re a disgusting murderer. 

Except, we are shown that this entire narrative of Shigaraki’s inherent monstrosity is bullshit. Better yet, it’s an abusive tactic. Designed spefically to prevent Shigaraki from ever wanting to get away from Afo’s control, and to make Shigaraki accept the role Afo chose for him. 

How do we know that it’s bullshit? well, because Tenko never actually showed that he felt any pleasure in taking lives. 

This was Tenko facing the father he supposedly “wanted to kill”. 

He’s crying, terrified out of his mind, asking for reassurance from his father, saying that he’s sorry, reaching out for help. 

Let’s not forget that his father was an abusive dickhead that hit Tenko every day. Yet Tenko still asks him for help. 

This is Shigaraki post-kidnapping when he was out on his first killing mission: 

Note how the hand that was supposed to “claim blood” and “follow his heart” closes in a fist and retracts instead of attacking. He’d just been hit in the face by those punks. He’s lying on the floor, nursing a swollen cheek. If he was a bloodthirsty monster, he wouldn’t have hesitated to kill. Yet, just like after his father’s abuse, Tenko endures the violence without physically fighting back. Because he’s not actually a bloodthirsty monster. 

Note how it’s only after Afo shows disappointment in him that Tenko starts to say that he wants to kill. He’s literally convulsing on the floor at the perspect of using his quirk again, the quirk that — let’s not forget it — orphaned him in a traumatic bloodbath. Let’s also not forget that the first time he saw the severed hands of his victims he was assaulted with so much self-disgust that he puked and cried on the floor. 

This is not a symbol of terror who wants people to die. This is a toddler gaslighted into embracing violence by being fed manipulative lies about his supposed desire to kill. 

Even as an adult, he repeats on more than one occasion that destroying things doesn’t make him happy. It doesn’t make the nausea and the despair go away. 

He’s simply doing it because rage is the only coping method that Afo taught him. He has embraced his role as the symbol of terror not because there’s something inherently monstrous about him, but because Afo purposefully raised him to embrace it. 

Even now, Shigaraki’s still following in Afo’s footsteps, constantly trying to make his Sensei proud, because he’s still under Afo’s abusive thumb. He has yet to break out of the gaslighting, or to see that Afo never cared about him, that Afo ruthlessly manipulated him for his own gain. 

From his (biased, unreliable) perspective, Afo is the only person who never denied his identity, who never tried to stop him from doing what he wanted. 

Except, that's false. Afo is unequivocally the most controlling person in Shigaraki's life. Even from Tartarus, Afo is still influencing Shigaraki's life, leaving “tasks” to be completed and “allies” for him to meet and exploit. Afo is still very much using that influence he has on Shigaraki's life to shape him into the kind of puppet he wants him to be.

He’s still dehumanizing him, still not even treating him as a human being, but only as a weapon that can be thrown at hero society to cause as much destruction as possible. Which brings me to the point I wanted to make to answer your original question: the same way Afo is doing all that, so is hero society. 

We are told pretty early on in the series that hero society has no intentions of sympathizing with Shigaraki. Times and times again, we are repeatedly informed that he's a manchild that lusts for destruction: 

In a grand show of Heroism, Gran Torino even completely abandons to his fate the grandson of his beloved colleague Nana. He sees no problem in letting him stay with the villainous mastermind that killed her, calling Shigaraki a bastard and a criminal instead of recognizing his victimhood. Implying that he deserves his fate because he chose to be a murderer for a living. 

In case that line of thinking doesn't read as bullshit to you by default, allow me to reiterate. Shigaraki didn’t choose to become a villain. He was kidnapped at age 5 by a centuries-old megalomaniac with a revenge scheme against All Might, and was raised in a basement secluded from all human contact for 15 years. The only times he was allowed to stay outside was when Afo forced him to kill. 

Shigaraki wouldn't be rampaging on heroes and dusting an entire city in a second, if heroes had bothered to rescue him from Afo at age 5. 

Heroes cannot simply wash their hands of him and pretend like villainy was ever a fully informed choice for him, not when he was groomed into it, raised with violence since a young age until he eventually normalized as a part of his life, the same way normal kids might normalize that bad behaviour ends up in getting grounded. Shigaraki was never punished for being violent. He was praised and encouraged to be. Again, because the environment he grew up in was not normal, but specifically tailored to be anything but. 

So when Gran Torino dismisses the fact that growing in an unhealthy, abusive environment might’ve affected Shigaraki's choices, he's essentially throwing him to the wolves. 

The bottom line here is clear: Hero Society isn't interested in sympathizing with Shigaraki's circumstances, because they want to believe the easier lie that Shigaraki is a monster. That Shigaraki longs for indiscriminate destruction, rather than address how it was possible for him to end up in Afo’s company in the first place. 

So they keep dehumanizing him and treating him like a dangerous object, an it, 

a “thing”

And even when they're informed that he's undergoing a clinical death procedure that the heroes now interrupted, putting his survival at stake, they don't even care about making sure that he breathes or that his heart beats again

because destroying the threat he poses is more important than preventing his death: 

And how is Shigaraki supposed to choose “good” morals over “bad ones” when the vestiges of his own grandmother can't accept his personhood? When his own family sees him as a monster and physically tries to prevent him from moving on with his life? When they’d rather he chooses death over literal survival? 

When Afo was the only person who offered a helping hand that never slapped his face or choked his neck? 

This is not to say that Shigaraki choosing Afo is good for him. In fact, in trying to obey Afo’s wishes, in forming alliances with the mla, and pursuing a power that would make him a deadlier weapon, he also caused the raid that resulted in Twice's death. So his attempt to become more like Afo is very clearly framed as a bad choice. 

But none of that takes away his redeemability from him. Actually, it only reinforces it. 

I've argued before that Aizawa is one of the key figures in the present conflict. As Eri’s (Shigaraki's narrative foil) caretaker and Shirakumo's friend, and as someone who was originally targeted by Ujiko, Aizawa should've been able to see Shigaraki's victimhood. Shirakumo had adopted Shigaraki like he had once adopted Aizawa. They were once both strays that Shirakumo took care of. Yet, Aizawa - a character based around the concept of rationality - decided that his grief overshadowed his logical thinking. He elected to ignore how Ujiko was literally experimenting on Shigaraki right in front of his eyes, the same way he had experimented on Shirakumo’s corpse. Instead, he continued dehumanizing Shigaraki and treating him as a weapon that needed to be taken care of. 

The result of that dehumanization is the chaos that follows. Shigaraki wakes up, activates Decay, and Aizawa is powerless to save Crust from getting caught in it. It's such a neat and blatant narrative punishment for his revenge plot you literally cannot read it any other way: Shirakumo died the same way. Protecting Aizawa from a hit he was meant to take. 

You see Hori's narrative intent here? 

The heroes called Shigaraki a manchild, a criminal, a thing, an it. They wanted him to be a monster. 

And now he is one, by direct consequence of their choice to dismiss him. So now it's the heroes’ job to correct their mistake, because merely treating Shigaraki like an object to dispose of only resulted in more destruction. The only way to stop him is to finally treat him like a person.