The following contains major spoilers for the Attack on Titan manga by Hajime Isayama, available in English through Kodansha US.
In 2021, the Attack on Titan manga concluded with the once-protagonist Eren Yeager almost wiping humanity from the face of the planet, only to be decapitated by his longtime friend, love interest and protector Mikasa Ackerman. The initial ending implied a shaky peace between the survivors of Eren’s genocide and a hopeful direction toward a future of prosperity for the Eldians, headed by Armin Arlert. Shortly after the first ending, the manga artist of the series, Hajime Isayama, released a secondary conclusion that showed the deterioration of peace and society, implying a circular fate when a child stumbled across a tree eerily similar to the one Ymir found hundreds, if not thousands, of years before.
Both endings sparked displeasure within the Attack on Titan fan base, leading Isayama to release a public apology. One of the main criticisms of the original ending was the poor writing of Eren's characterization. The character’s intentions were carelessly written and the plan he concocted was a reckless gamble that did not entirely make sense. The surface-level attempt to have the supporting cast sympathize with Eren, to the point of tears upon his death, was a shallow form of forced emotion. However, there is a spark of hope within the fan base that the direction the anime is following may differ from the manga.
The Possibility of an Altered Anime Ending in Attack on Titan
Normally, a desire for an altered ending from an adapted source material is a pipe dream. The story is usually set in stone and the anime plays out the same, with little deviation. However, the changing of an ending is not entirely unheard of. The anime Death Note had a different ending to that of the manga, even if only slightly, but it changed the dynamic of Light Yagami’s final moments. The precedent exists for the chance to see an anime original ending, but for Attack on Titan, it would likely need to be considerably different to appease the discontent within the fan base.
Due to the indecisiveness of the manga ending, one being a betrayal to the fans and then switching to betray the tone and themes of the series, there is certainly enough evidence to suggest that the producers of the series may consider changing it. It is not a hidden secret that the fans were unhappy with what was offered in the ending; with this information, MAPPA could be looking at the other possibilities that Isayama considered for his endings, such as the implied ending in the music video "Akatsuki no Requiem" by Linked Horizon.
Attack on Titan's Anime Foreshadowing
There is the belief of an alternate timeline being followed in the anime. The whole concept of memory time travel is a complicated form of storytelling, but it allows for the possibility of differing outcomes. Within the manga itself, Eren witnessed the events through future memories, which unknowingly set him on the path of a predicted fate. However, eagle-eyed viewers have noticed a few variations from the manga and anime that may foreshadow the chance that the manga is one timeline or viewed future, while the anime is a separate branch from that timeline.
One major difference between the manga and anime is the memory shard scene as Eren is transported into the Paths. There is a clear difference between what the manga portrayed compared to what the anime did. This change hints at a different timeline being viewed by anime Eren, possibly implying that the manga is a previous timeline experience, while the direction of the anime may be Eren’s second attempt to change fate. Another brief moment -- Eren’s arrival in the Paths in the manga -- is one of confusion, while in the anime, he shows familiarity with the location.
Timeline Theories Within the Attack on Titan Fan Base
A widely speculated theory is about the change in Eren’s jacket and shirt color when he was young in Season 4, which changes from red and green in the manga to black and gray in the anime. Such small changes could simply be artistic choices by MAPPA, but the intentional change could symbolize the effects of a time loop, which is implied by the manga itself, and the perception of separate timelines that Eren is attempting to break free from. The anime is littered with minute differences, some as small as Mikasa turning right instead of left, but combined, they create a vision within the eyes of the fan base of intentional shifts from the source material, foreshadowing a diversion from the manga ending.
The possibility of a different ending for the Attack on Titan anime is not out of reach for the fan base. While the ending had its strengths, there were some tonal concerns and characterization shifts that did not fully reflect what had been built up throughout the series. Either way, with Part Three of Season Four on the horizon in 2023, audiences will soon have their questions answered about whether they will witness a new -- and hopefully preferable -- ending or if the anime will remain true to the source material.