Eri has been a huge part of the Shie Hassaikai arc of My Hero Academia as we discover more about her and the people she’s been associated with. The arc during this season turned into a rescue mission for Deku and the rest of the heroes as they try to save Eri from villain Kai Chisaki a.k.a. Overhaul and the rest of his gang from the Yakuza. Eri’s background has been a bit of a mystery throughout the arc, but we slowly learn what she’s capable of as far as what her Quirk does. Here’s what we’ve gathered regarding the mysterious power that Eri carries.
10 Her Power Is Called Rewind
It was during Deku’s fight with Overhaul that we discovered in a flashback that Eri has the ability to rewind anyone whom she comes into contact with. Her ability manifested when she used it on her father, causing him to vanish out of existence. This caught Overhaul's attention, deciding to use her ability to take out anyone’s Quirk from his or her DNA.
We got to see her use it in battle when she lends her power to Deku in order to cure his injuries and use his One For All at maximum strength. Eri’s power is something she doesn’t seem to have control over when used exponentially.
9 Eri Can Make Anyone Quirkless With Her Power
Throughout the Shie Hassaikai arc, we saw a potential danger to heroes everywhere when a bullet has been popping up in the black market, which could take away anyone’s quirk. It turns out that Overhaul has been using Eri’s blood to develop these bullets that can erase anyone’s quirk in order to enact his plan to fix human society by taking away all quirks.
It’s definitely a power that is a major game-changer for the villains to use for their own benefit against the heroes. Because of this, it could pose a danger to any hero out on patrol with these bullets out in society.
8 Her Power Only Works On Living Creatures
As mentioned by Overhaul, Eri’s rewind ability only works on the living, so inanimate objects won’t work with her power. With her quirk, Eri can rewind any living organism to its earlier state. So, she can basically heal injuries or make any person younger.
It does explain how she can take a person’s quirk out of their system if she can rewind that person to an earlier state before his or her quirk manifested. We saw that with Mirio losing his quirk from one of the bullet’s carrying her blood and making her father disappear out of existence when she was younger. It’s a power that can be useful or dangerous to a living thing if not handled properly.
7 Eri’s Quirk Is Actually a Mutation
Despite getting her quirk at birth, Eri didn’t get her ability from either of her parents. As it turns out, Eri’s power is a mutation that has been developed in what is known as a quirk singularity. As the next generation of a family tree continues, those children could develop quirks that are no longer like their parents and evolve into something more powerful like Eri’s.
We saw her demonstrate this powerful ability when she erased her father from ever being born and healing her wounds automatically. It does explain why Eri has been covered in bandages, as Overhaul has been using her blood to create the bullets he needs to enable his plans to make the world free from quirks. It’s quite as horrifying as it sounds since Eri doesn’t have quite a hold on her power just yet.
6 Her Power Is Somewhat Similar to Overhaul’s Quirk
Overhaul saw the potential of what Eri’s quirk can do and sees that it has the same effects as his own power. With Overhaul’s ability, he can break down and recreate whatever he touches, making him a powerful and deadly villain. Eri’s power is a much more powerful version of Overhaul’s where she can basically rewind the entire human body.
It’s simply one half of Overhaul’s quirk, but it's taken even further than what he can do. Overhaul explained that quirks are developed and progressed in the human body over time. While his power can destroy and re-create human parts of the body, Eri can rewind the development of the body to an earlier state.
5 Her Horns Are The Source of Her Power
Based on the anime and manga, most of her power comes straight from her horn located on her forehead. Both mediums have displayed what Eri’s quirk does to her body, but the manga seems to show it much more clearly. There’s a connection between Eri’s horn and her quirk when she activates her power.
Even though her blood carries her quirk, it is her horns that help build upon her ability. We can tell that her powers are dormant when Eri’s horns are small, so she’s pretty harmless. However, when her horns start to grow, that is when she becomes much more powerful and hazardous to those around her.
4 Her Quirk Can Build Up Over Time
Thanks to Eri’s horn, her quirk can accumulate the more she uses it. The only catch to her power is that she can only release it when it builds up over time. It seems like the only way her attack can be used is when her horn grows.
Since her horn is the source of her power, it makes sense that her quirk needs to be fully developed in her body in order to activate it. We saw that power unfold when she used it on Deku to increase his attack power during his fight against Overhaul. It’s a pretty powerful quirk, but it does seem to need a lot of build-up in order to use it.
3 Eri’s Emotional State Can Make Her Quirk Dangerous
It seems Eri’s quirk activates when she is in some kind of emotional state. We can see that happening when she gets upset to see those around her getting hurt because of her. When she was clinging onto Deku, seeing how much danger he was in made her quirk come out to help him in battle.
The only problem is that she didn’t seem to know how to stop her quirk from overpowering him. Once she learns how to keep her emotions in check, it’ll be easier for her to control her immense power because it is something that can be done under supervision.
2 Eri’s Power Could Potentially Help Others Like Her
Eri’s ability is certainly one that needs time to master. In quirk society, it is known that there are people with quirks that could be powerful enough to possibly destroy civilization if they aren't controlled. Once Eri is able to control her quirk, she can possibly be able to help others who are also having a difficult time controlling their power.
Since she can rewind a person before his or her quirk manifests, it could help a great deal in helping manage a powerful and unstable quirk. This kind of power that Eri has could change society for the better once she has a grasp on her ability.
1 Her Quirk Can Possibly Help Mirio Regain His Power
After losing his quirk, no one was sure if Mirio would ever get his power back. According to Eraserhead, it seems like Mirio could regain his quirk through Eri. If her power can take away someone’s quirk, it’s possible that she can put it back as well. It would require some training for Eri to learn about controlling her abilities and see what else she can do with her evolving power.
If Eri’s ability can heal a person, it’s possible she can also return a quirk to a person’s DNA. It does put some hope on Mirio knowing that he can get his power back someday, and Eri may be the key to helping make that happen.