WARNING: The following contains spoilers for Attack on Titan Season 4, Episode 27, "Retrospective," now streaming on Funimation, Hulu and Crunchyroll.
The unlikeliest duo in Attack on Titan sealed the Jaegerists' fate when Theo Magath and Keith Shadis blew up the only ship -- along with themselves -- capable of pursuing the Marleyans and Scouts. The Azumabito's flying boat will take half a day to prep for flight, and the group can't stay on Paradis Island without an endless conflict. Planning to tow the flying boat to Odiha to service it away from the Jaegerists and ahead of the Rumbling, the group would never have escaped if it weren't for the actions of Magath and Shadis.
As the fight at the port was tilting in the Jaegerists' favor, the train carrying their reinforcements was mysteriously blown up. Shadis quickly arrived, confirmed he'd blown up the train, and joined Magath for a suicide mission to prevent any stragglers from being able to follow the Marleyans and Scouts hoping to stop Eren and the Rumbling. As Hange and Jean, along with Pieck and Gabi, watched their respective instructors blow themselves up, Attack on Titan has come full circle in a heartbreaking way. The students are now the masters by necessity as the command structure of both Paradis Island and the Marleyan military have completely crumbled.
Keith Shadis Is No Longer A Bystander in Attack on Titan
The former instructor of Paradis Island's Cadet Corps -- and Commander of the Survey Corps before that -- Keith Shadis has been a part of Attack on Titan from the very beginning. The commander of the 104th Cadet Corps oversaw the training of the most problematic graduating class of all time, considering its Top 10 contained three Marleyan spies / Titan Shifters, as well as the world's greatest enemy, Eren Jaeger. Shadis has long been down on himself for being an unremarkable man in a remarkable world. Handing over command of the Survey Corps to Erwin Smith, whom Shadis believed was better suited to save humanity, his inaction has been his defining trait for most of his life.
Shadis has considered himself a bystander his entire life as he watched people like Erwin, Grisha Jaeger and even Eren change the world inside the Walls in ways he had only ever dreamt of. Shadis' story has come full circle now that he's taken decisive action against the Jaegerists, blowing up their reinforcements so his former students could save the world. If the Jaegerists' backups had arrived, the Marleyans and Scouts surely would have been overrun and the world would have been doomed to the Rumbling. In his final act, Shadis did the bravest, boldest thing he could possibly do by standing against the Jaegerists -- even though stopping the Rumbling may doom Paradis Island.
Theo Magath Took Responsibility For His Part In Marley's Awful Deeds
Introduced as the commander of the Marleyan military's Eldian Unit, Theo Magath was initially just like any other Marleyan. Viewing Eldians, even those serving Marley, as hideous devil spawn who deserve to suffer for their ancestors' crimes, the renewed war between Marley and Paradis Island forced him to reexamine his own ideals. Magath clearly became attached to the children in his charge over Marley's Warrior Program, particularly Gabi Braun. Gabi's fanatical dedication to proving herself to be a "good Eldian" opened Magath's eyes to the cruelty of indoctrinating children to fight in a deadly and bloody war.
After some growing pains in teaming up with Eldians, Magath expressed his heartfelt regret for his past treatment of the Eldian race. Like every other Marleyan who's spent significant time on Paradis Island, Magath learned that the "Island Devils" are ordinary people just like anyone else. His final sacrifice is an especially heroic one because he did not blow himself up to save Marley. From Hange's deductions, Magath knew Marley was already doomed to the Rumbling no matter what. Instead, he sacrificed himself to atone for the fact that Gabi and Falco never got to have normal lives, and stopping the Rumbling is their best chance to do so in the future.
