My Hero Academia Theory Suggests How Shigaraki Might Be Saved
My Hero Academia fans have a popular theory about how Izuku Midoriya and his fellow heroes are going to pull off the seemingly impossible feat of "saving" Tomura Shigaraki. Deku made such a declaration after facing a power-boosted Shigaraki in the First War Arc when it was revealed that Shigaraki's master All For One had always planned to take possession of his protege's body and mind as a pathway of resurrection. However, as the Final War Arc is now unfolding it's become clear just how parasitic All For One's hold over Shigaraki really is.
...So how can Shigaraki be "saved" in the literal sense, and redeemed according to the thematic framework of the series?
The popular theory is that 'saving Shigaraki' will be a goal that is achieved by bringing the story back around to the character of Eri!
Eri was introduced in the Shie Hassaikai Arc of My Hero Academia, as the "secret ingredient" of Overhaul's quirk-erasing bullets black market arms trade. Eri's quirk is "Rewind," which allows her to reverse a living person's body back to an earlier state of being. It was always mentioned that Eri could achieve feats like reducing someone to a younger age, healing bodies to pre-injured states, and undoing bodily modifications. At first, the power was clearly introduced to both shake up hero society (via the quirk-canceling bullets) and provide the ultimate solution to the threat of Overhaul; later it was just as clear that Eri's training in her power would provide the path for Mirio Togata's Permeation quirk to be restored.
However, now that we've seen All For One complete the body enhancements to Tomura Shigaraki, and take more complete control of the boy's mind, suddenly there's a new and more significant window of opportunity for Eri to shine. With her newly controlled abilities, Eri could significantly tilt the battle in the heroes' favor (and save Shigaraki in the process) by simply rewinding the villain back to a time when he was still "Tenko Shimura" – possibly before his horrific quirk power ever kicked in and made his life one of gruesome death and suffering.
If AFO-Shigaraki gets hit with the rewind effect, All For One the man will lose his would-be unstoppable vessel and have to face the heroes (and Izuku) in a final battle between the One For All and All For One powers. It might be even more fitting if Izuku's compassion to save "Tenko" gives him the ally he needs to truly destroy All For One for good, using Teno's disintegration quirk.
How do you want to see Shigaraki's story play out in My Hero Academia?