Warning! Spoilers ahead for My Hero Academia chapter 330!
Ever since All For One started preparing Tomura Shigaraki's body to serve as his vessel, My Hero Academia fans have been anxiously waiting what that final form will look like - and it's much darker than they or anyone could have imagined.
Before their unveiling, a flashback showed All For One clearly separated from Shigaraki. All For One was obviously in hiding, and since fans last saw the villain fleeing in Shigaraki's body to an area where they could complete their transformation with no disruptions, readers assumed the scene transpired after All For One took over his apprentice's body and that they had separated for some reason. Shigaraki's confrontation with America's hero Star and Stripe, however, only left readers with more questions than answers when she asks if he were All For One, to which he responds by saying, "Good question. What exactly am I?"
The revelations presented in chapter 330 of My Hero Academia bring to mind the idiom "ignorance is bliss." All For One is clearly in control of Shigaraki - for now. Early on in the unofficial translation, amateur translators note that the speaker is obviously All For One because the villain uses the pronoun "boku" when Shigaraki would have used "ore" had he been speaking. Later both the unofficial translation and Shonen Jump's translation by Caleb Cook definitively prove that the villain Star and Stripe is fighting is, in fact, All For One by how her World Order quirk manifests. Star and Stripe can impose any rule on anything so long as she touches it first. When she grabs All For One, Star and Stripe's new rule is "If Tomura Shigaraki moves at all, his heart will stop." But "Shigaraki" later moves, and his heart doesn't stop.
Even though she's clearly fighting against All For One, he and Shigaraki are currently in a limbo-like state because both of their consciences exist, but not in the same way as other similar host and parasite relationships like Marvel's symbiotes. The border between both personalities is hazy. At one point, All For One says, "I can truthfully declare that I am Tomura Shigaraki but at the same time, there is no doubt that I am also me." There isn't a clear distinction between them because they sort of blend together, unlike how Marvel's Eddie Brock can clearly differentiate himself from the Venom symbiote. Meanwhile, All For One originally intended for Shigaraki to become him. But Shigaraki's hatred caused the transformation to mutate. They are now going to fuse into a completely new being. The fusion just hasn't finished yet.
Although the concept of them becoming a new villain entirely is captivating, this current limbo-like state is definitely more terrifying. Of course, being the twisted and deranged monster that All For One is, he's clearly reveling in the experience. But to readers, trying to comprehend what they're going through is unsettling. It's easier to wrap one's mind around the concept of a parasite's voice speaking in the host's mind or a parasite forcing the host's consciousness into the the background to "watch" them as they control the host's actions like a movie.
The unsettling nature of this transformation aside, My Hero Academia is setting up a moment that is sure to garner strong reactions from fans. Two captivating characters whom many readers are passionate about are being replaced by a fresh new villain. This phenomenon is akin to them dying. Despite being upsetting, readers will still have strong ties to their replacement, who will basically be an entirely new villain. Usually when series introduce anybody new so late in the game, the effort falls flat. But it won't now because they won't be entirely new. It's a win-win. My Hero Academia readers will experience the excitement of getting a new villain without the drawbacks while undergoing a strange mourning period for the loss of Tomura Shigaraki and All For One that will only enhance their appreciation for the series overall.