WMG / Talentless Nana

Per wiki policy, Spoilers Off applies here and all spoilers are unmarked. You Have Been Warned.

Nana will kill Moe.

Given how her reality was shattered by her former superior, Nana would be more than likely to snap again when she learns that Moe was keeping the truth about what happened to Michiru from her. So much so, she would kill her without a second thought. It could also be that Jin would stop Nana from carrying this out due to his shared distaste of killing, but he also raised this very scenario to Nana earlier on whether or not Moe could be trusted.

Tsurouka made Nanao do something to Moe's grandmother.

As Moe had yet to kill any of the students, Tsuruoka would most definitely have Nanao do something grievous to her grandmother's body to force Moe's hand.

Nanao will kill Jin.

Since Jin can transform into Nanao, it's possible that their simultaneous use of biomanipulation could cancel each other out. Therefore, Nanao needs to attack Jin before the latter can transform, since the former would no longer be a threat otherwise.

Nana is Kyoya's sister.

Kyoya's said that his sister is younger than him, but the last round of killings on the island took place five years ago, with Jin's class. Assuming that Kyoya is aged between 15 to 18 years old, which are the ages for first to third year high schoolers in Japan, his sister would have been at most 12 at the time. It's not totally unbelievable that she went to high school at that age, since Talentless Nana already plays pretty fast and loose with its continuity, but Nana also makes specific note of the fact that Kyoya didn't bother checking the five year old corpses for his sister—this could mean that he knows she wasn't on the island five years ago, and that she came there more recently.

• On Nana's end, we know that she has a much older brother who left home before she could remember him. Her and Kyoya seem to be about the same age, but because we don't know everything about his immortality, and taking into account the running gags about how he speaks in an old fashioned way, likes old games, and doesn't understand modern slang, it's possible that Kyoya is actually a good deal older than he looks. Soon after Nana's older brother is mentioned, we also learn from her conversation with Michiru that she's actually an incredibly messy person by nature in the same way that Kyoya is, and this one is admittedly a reach but that scene might actually intentionally call back to the first scene in Kyoya's room, by emphasizing their Trash of the Titans tendencies and feelings about manga.
  • The first thing we learn about Kyoya's sister is that she had pigtails, which Nana is shown to have had as a kid, and that her hair was good for Kyoya to fidget with, like Nana's. Another complete reach, but Nana's hair is white at the edges, though not the same shade as Kyoya's.
    • If Kyoya is Nana's brother, it gives her parents a concrete reason for wanting to protect the Talented, beyond just being good people. He might have left home because it was safer, and he may have come back after all this time because he heard about what happened to them.

• The biggest question, if this theory is true, is why Kyoya doesn't recognize Nana. It's possible that either one of them is using a fake name, which would explain their different last names, but there's also the matter of Kyoya's journals. When he and Fuko find them (at least a few dozen, in a box labeled "important," all of which he says he needs to keep with him), he's visibly upset, and then immediately tells her that he'll explain his weakness before the scene changes. That seems to imply pretty clearly that Kyoya's weakness is related to his memories, likely that he loses them when he uses his talent, so it's possible that part of why he doesn't recognize Nana is that he just doesn't remember much about his sister.

• Jossed. Kyoya's sister, Rin, debuts as a separate character in Chapter 76.

"Jin" is Kyoya's sister.

All we know for sure about "Jin" is that they were a part of the last round of killings on the island five years ago and that their Talent gives them the ability to disguise themselves perfectly as anyone (as well as use other people's powers). It's possible that they're actually Kyoya's sister, laying low or playing out a long game of her own. There isn't much evidence for this one, aside from the timeline matching up and "Jin" hanging around Kyoya as a cat.

• "Jin" and "Rin"... kinda rhyme, huh? On a more serious note, Chapter 79 shows an image of a butterfly when Kyouya's sister Rin discovered her talent, the same butterfly that Jin transforms into every now and then. It is also noted by Tsuruoka that Rin's talent is highly powerful, and it took multiple attempts and effort just to subdue her, and Jin hasn't appeared so far after the Time Skip.

• Possibly confirmed as of chapters 93 and 94, where we see the implication that Rin transforms into "Jin", and her flashback to her time in the Island shows that she met the actual Jin Tachibana.

Kyoya is Older Than He Looks

As above, his younger sister vanished at least five years ago, and she was a high school student. If she was in high school, he must have been high school aged or older, so he should have graduated. If he's older than he looks due to immortality, that solves the problem.

• Chapter 77 also shows that he was in college a few years prior to his sister's disappearance.

The series is set as a prequel to "My Hero Academia"

In MHA it's mentioned that before the society managed to become the way it is now, a lot of people with quirks started to use them for evil, with utter lawlessness existing as no one knew how to handle things at the time, allowing criminals to build their empires (one of which was All For One) and fighting in the streets with superpowers was a natural occurrence, just like it was mentioned in Chapter 2 of TN. It's also very likely that All For One might had some influence in making government fascist in the 3rd big arc, making strict laws for both Talentled and Talentless citizens.