In My Hero Academia season 4, Mirio Togata (Ricco Fajardo) loses his "Permeation" quirk, an ability that allows him to move through solid objects, after being shot with one of the Shie Hassaikai’s manufactured bullets, which contains a quirk-erasing drug. In the episode “Bright Future,” Sir Nighteye (Brandon McInnis) uses his quirk “Foresight” to peer into Mirio’s future and claims that Mirio will still become a great hero despite the fact that he no longer has a power, but what future did Sir Nighteye truly see for Mirio?
During the first half of season 4, Izuku Midoriya (Justin Briner) and Mirio, as part of their hero work study, aid the Sir Nighteye Hero Agency in an investigation into the Shie Hassaikai, a Yakuza group that’s been holding a young girl named Eri (Emily Neves) hostage and using her time-rewinding quirk to produce a quirk-erasing drug. After each of them individually battles Overhaul (Kellen Goff), the leader of the Shie Hassaikai, Mirio is left quirkless. Midoriya saves Eri and defeats Overhaul, while Sir Nighteye succumbs to his injuries. In the episode “Bright Future,” before Sir Nighteye passes away, he uses his power to look into Mirio’s future and claims that Mirio is destined to become a great hero. However, a comment Nighteye made to Midoriya earlier on in the episode suggests that Nighteye may have seen a different future for Mirio than what he claims.
Before the incident at the Shie Hassaikai headquarters, Sir Nighteye operated under the belief that his quirk Foresight should be used only when absolutely necessary and as minimally as possible, especially since every single future he’s viewed using his quirk has come true. With this in mind, Nighteye began to fear that every future he viewed implementing Foresight caused that future to be the only possible outcome, including the gruesome death he foresaw for his former partner and idol All Might (Christopher Sabat), which he predicted five years prior. When Nighteye used his quirk to view Midoriya’s future, he predicted that Midoriya would die fighting Overhaul and that the villain would escape with Eri. However, when the incident concluded differently with Midoriya saving Eri and arresting Overhaul, Nighteye developed another theory as to why Midorya’s future changed so drastically.
When Sir Nighteye is on his deathbed, Nighteye suggests to Midoriya that the collective energy from everyone present during the infiltration of the Shie Hassaikai compound affected the events. According to Nighteye, despite foretelling that Midoriya would die in his fight against Overhaul, the united belief that they could rescue Eri shared by Ochaco Uraraka (Luci Christian), Tsuyu Asui (Monica Rial), Eijiro Kirishima (Justin Cook), and the rest of the Pro Heroes converged on Midoriya and brought that outcome into being. With this new theory in place, Nighteye therefore feels comfortable peering into Mirio’s future, knowing that no matter what future he sees, it’s capable of being changed.
While it may be possible that Nighteye did see a future where Mirio regains his quirk (thanks to Eri’s time-rewinding ability) and eventually becomes a professional hero, it is more likely that Sir Nighteye saw an entirely different future in store for Mirio and simply told him a more positive outcome so that his belief in that future would make it come true. Having employed Mirio as his sidekick at his own hero agency for the past year, Nighteye knows that Mirio has a very positive and tenacious disposition and that, with a little encouragement, his pure belief in himself and his dreams will push him to make his heroic future a reality, regardless of whether or not his Permeation quirk is ever reattained. While only time will tell if Sir Nighteye's prediction will come true within My Hero Academia, it's clear that Mirio's future remains bright as long as he believes his dreams are attainable.