The following content contains spoilers from My Hero Academia, Season 6, episode 18, currently streaming on Crunchyroll. The aftermath of the first wave of the Paranormal Liberation War has left society in utter chaos as civilians begin taking crime-fighting into their own hands while casting their Heroes out into the cold. The previous episode takes a deep dive into the Todoroki family's past, evaluating the roles everyone played in leading Toya toward villainy and giving Endeavor a much-needed boost to rejoin the fight.
Creators have seemingly forgotten the whole reason My Hero Academia fans gather around their screens every week: for Deku, of course! However, the beloved Hero has essentially been absent for the entire second cour of Season 6, but his time to shine has finally arrived.
The Users' Dynamic
Unbeknown to viewers, Deku and Shigaraki aren't the only ones who have been undergoing some power upgrades, as One For All also suddenly began evolving out of the blue, starting four months before the Jaku disaster. Before, the past Users only existed within "the spaces between fluctuation;" however, now, they have form, functionality, and a lot to discuss with Deku. Strangely enough, the Second and Third Users refrain from joining the chatter and stand to the side, facing the wall as if two disobedient kids in a timeout. In contrast, the chatterbox Forth wielder, Hikage Shinomor, takes the initiative to explain why they are all gathered here, and, needless to say, it's not good news.
The topic of mortality comes up as Hikage reveals that he only lived for forty years (possessing One For All for eighteen of those years), and, after All Might did some digging, his cause of death was deemed a natural passing due to "old age." Yagi, on the other hand, managed to hold onto his Quirk for a full forty years before his body started showing signs of distress, raising some important questions when comparing All Might and Hikage's experiences.
The Power of the Quirkless
One For All's past Users have concluded that possessing multiple Quirks is bound to shorten the wielder's lifespan significantly, due to the strain inflicted upon their bodies (much like Dr. Ujiko's Quirk Singularity Doomsday theory dictates.) Up until recently, however, the Users came with predisposed powers and essentially incorporated their Quirks with One For All, causing their cups to overflow as their genetic structures became overwhelmed. Yagi, on the other hand, joined the ranks as a Quirkless tribute with an empty cup, therefore possessing enough room to encompass the potency of One For All. His Quirklessness resulted in a lack of internal competition between dominating Quirk Factors, granting him the opportunity to continue fighting and living for longer.
Fortunately, Izuku is blessed with the same advantage; however, due to the exponential growth of their combined powers, it will now be impossible for One For All to be passed along. That is, unless another Quirkless prodigy happens to cross paths with Deku, which is highly improbable considering the current dynamics of society (whereby the majority are born with powers.) It appears Deku may just be the Final User and One For All will die with him (hopefully in the distant future, at least!)
Interestingly enough, many believe that people's consciousnesses get "etched into their Quirks," essentially combining one's powers with their soul (almost like the relationship between Stand and User in JoJo's Bizarre Adventure.) Therefore, One For All's former wielders didn't expect All Might to get a seat at the table; not because he is undeserving, but rather due to his original Quirk factor deficiency. One For All has made such an impact on Yagi that his soul has essentially fused with the Quirk, much like the past Users, subsequently providing a useful link between the two "worlds." Back in the realm of consciousness, All Might has a semblance of what's happening between the Users, even picking up vague details about their conversation while his "soul" silently observes the scene from the other end.
Shigaraki's Fate
One For All Users are apparently all in agreement that Shigaraki is completely irredeemable; however, Deku believes otherwise. Thankfully, the youngster manages to find his voice (quite literally) and make his case, attempting to convince the others that Shigaraki needs rescuing, not more conflict. He goes on further to explain that aggression has become the first response to resolving issues with Villains and that, maybe if he knew more information about their past, he mightn't need violence to resolve the issue. If the fundamental source of evil can be addressed, a potentially peaceful outcome could ensue.
Deku surmises that One For All's purpose was never to add to the death toll and that All Might isn't the Symbol of Peace for nothing; he provided hope and safety for society as a respectable pillar of strength, without adding more brutality to the equation, like some other currently questionable Heroes. His passion overwhelms most of the past Users (save for the uncooperative pair in the naughty corner) and Yoichi, Nana, and the rest rally to Deku's side as he attempts to protect Shigaraki from, well, himself.
Letting the Cat Out of the Bag
Back in "the real world," three days after Toya's public statement, the top three Pro-Heroes address the masses and implore the civilians to seek safety among the walls of U.A. High School. Endeavor begs everyone to cast their blame and discontent toward him and him alone (which Toya takes as a direct challenge), thus allowing the other Heroes to go about their business of cleaning up the streets. He corroborates Dabi's story by acknowledging their kinship; however, the Villain isn't correct on all counts, seeing that Best Jeanist is clearly alive and kicking.
Hawks steps in to admit that he killed Twice after assessing that it was the only option to prevent further death and destruction, and asks for forgiveness regarding his secrecy regarding his own father. Despite their best efforts, Endeavor, Hawks, and Best Jeanist seem to have done little to quell the distrust; "If Heroes were defined as those whom people call for, then Heroes disappeared that day."
Meanwhile, Deku has regained consciousness and swiftly cut ties with his loved ones for their own safety; he is well aware of the target on his back, no need to share the danger with others. Leaving a handwritten note for each member of Class 1-A, Deku divulges his Quirk's secret and disappears into the shadows as he embarks on a solo mission to save Shigaraki; "The final act begins" with "Full Power." Best Jeanist and Hawks have also been updated on the matter, while Endeavor has connected the dots himself (it is unclear, however, if he has received confirmation regarding his suspicions.)