Can you please explain Shigaraki's feelings in the last chapter? What did talking to Hana mean to him? Did he hate his mother? And where Nana was from, he literally knew her from the photo.

alright symbolism time.

Shigaraki walks down a pathway that is made up of decayed parts of a house in front of, behind, and breaking into pieces around him. He looms far above a cityscape in the background. Also significant is the number of severed hands that are breaking into dust as they reach out towards Shigaraki Tomura. 

There’s several important images associated with this, so let’s just break them down one by one. 

Eri who suffered incredibly similiar abuse to Shimura Tenko reflected this when Midoriya reached out a kind and helping hand out to her. That every hand that had ever reached out to her before that point was only to use her, or harm her but Midoriya’s hand was different. Midoriya’s hand was kind, and that was the first time a person reached out to her in such a way. She didn’t know anything else before that point. 

Hands, are symbols of heroes saving people. However, in this society not everybody gets saved. While hands are a universal symbol of reaching out to lend a helping hand to someone else, they don’t mean that for Shigaraki. 

Shigaraki lived through a situation where if just one person had extended a helping hand things would be different, but nobody did and because of that Shigaraki can’t believe hands are meant to save people. He sees hands in the cityscape but the hands are slowly decaying away, because he doesn’t believe a single one of those hands is going to help them.

Consider the situation as well. The heroes are not here to help him. He’s a thing that they need to kill. Shigaraki’s heart stopped last chapter, but even though heroes aren’t supposed to kill people the hero attending him makes no attempt to recessitate him.

The heroes who save people aren’t even attempting any kind of CPR. Like, if a prisoner gets sick, the prison guards aren’t supposed to go whatever he’s a crimminal and just let him die. If a suspect gets injured in a police chase, the police are SUPPOSED to call an ambulance. This raid has shown us two instances already, first with Hawks and now with Shigaraki that heroes are perfectly willing to kill people. There is nobody here to save Shigaraki, no single person in the world had extended a helping hand out to him, even the heroes just see him as a thing to be destroyed. 

Which is why it should be no surprise at all that Shigaraki walks towards the one person who shows him a hand. 

What’s important is in the feelings towards his family Shigaraki deliberately contradicts what he said earlier. 

Shigaraki narrates that he hated everyone in that household. That he wanted them to crumble away. That he hated them, and therefore some of his quirk activating and decaying them must have been on purpose. 

However, when actually confronted with them and speaking with them Shigaraki deliberately contradicts this. He says he’s built up hatred and resented his sister, but when talking with her in a relaxed way he begins to say he’s already forgiven her. 

When his mother asks him about the itch, he not only reassures her that he’s fine but he also begins to return to the child he was again. 

Even when knew his father was behind him he doesn’t look at him hatefully at first. He smiles at his father, and then looks surprised when he sees his father’s hand disintegrate. 

Shigaraki’s narration says that all of his negative emotions piled up, leaving him no choice but to kill his family. However, that is a lie because when he’s shown his family’s loving side in his dream-like state he responds by becoming the gentleboy he once was. It’s only when confronted again with his father’s abusive hand that he becomes Shigaraki again TO PROTECT HIMSELF. 

Shigaraki’s claims that he hates his family, that he wanted to kill them are contradicted by how gently he behaves when talking to his mother and Hana. He was even about to tell Hana that he already forgave her, or at least that he wasn’t angry anymore. That’s very different then I still hate them after all this time and feel no guilt over their death, which is what we’re TOLD Shigaraki feels but are SHOWN something else entirely. 

His family calls him Tenko, and he becomes Tenko again. All for one calls him Tomura, and he snaps back into awareness and becomes Shigaraki Tomura once more. The question is if he doesn’t hate his family, doesn’t want to kill them why does he choose AFO over them?

The answer once again has to do with hands. His family love him, but they don’t care about him as a person. They don’t care about his wants and needs. Shigaraki is walking towards life, the only way to move forward, and his family demands that he stay dead. They deliberately try to chain him down because living is a villain is somehow WORSE than dying. Shigaraki is siding with AFO yes, but he’s also siding with the one person who said it was okay for him to live, to keep walking forward. 

Nana, and the rest of his family act so entitled to Shigaraki. They are the ones who mistreated him, but they also insist that he can’t forget about them. Shigaraki does love his family, but it’s also important to note that at the same time he doesn’t know the love of a family that accepts him for who he is. The hands that are supposed to reach out and take care of him, have always strangled him, held him down, beaten him and tried to control him. That’s why even if that family is trying to talk Shigaraki down from destruction, he can’t listen to them even now. 

Because they never asked what he wanted. They never thought about him as a person, his own individual needs as a person. They all acted selfishly. Nana acted selfishly when she decided to abandon her son and cut all ties with him, instead of giving up being a hero. Kotaro acted selfishly when he forced Shimura Tenko to give up his dream so Kotaro could keep having his ideal family that he had total control over and beat him when Tenko didn’t. The other members of his family cared more about the peace of the household then they did about Tenko’s own feelings. Every single person has been seflish and demanded something of him, and Tenko doesn’t really know the unconditional love and acceptance of a family because he’s so used to being denied by them. 

Shigaraki loves his family, but he hates what they do to them. He hates how they make him seem so small, and make his needs feel like they’re not important. That’s the nuance. 

He doesn’t want to be denied. Of course he goes towards AFO. He thinks AFO is the one person who accepted him. He’s not going to turn his back on the one person who showed him a small form of acceptance, for the sake of people who never accepted him once. For Shigaraki hands aren’t there to help him, they’re there to hurt him and hold him back because he’s never been shown a genuine helping hand. 

As for why Nana is there she exists in the vestiges as some kind of consciousness. It might actually be the same Nana that shows up in OFA, because the two quirks are connected. Which is why Deku is made aware of the fact that Shigaraki woke up, because Shigaraki is the one who was passed the real AFO quirk, and therefore Nana existing in some form in both quirks most likely alerted Deku. 

There’s also a theory that Nana is the hand which grabs Shigaraki by the back of the head, which All for One had and gave to Shigaraki, because All for One was the one to kill Nana of course. That’s been pointed out by several people who are not me. 

When would A*O have had the chance to swap out Tomura's potential Quirk -- unless he was essentially stalking him from the beginning?

Good question, that’s one of the holes in that theory. A*O did seem to intentionally take in Tomura for being Nana’s grandson, so I’m assuming he kept tabs on the family, but who knows