The Attack on Titan manga by Hajime Isayama comes to a conclusion in 2021 after 11 years and 7 months. A narrative that has captivated readers all around the world comes to a satisfying and emotional end in Chapter #139, "Final Chapter: Toward the Tree on That Hill." Though not everyone survives, despite how grim the series has been, there is hope for more of its primary group than viewers may anticipate. Here is how Attack on Titan came to a conclusion and what Eren Jeager's ultimate destiny was.
The end of eren's life. Don't be sad about it
In the penultimate chapter, Mikasa, Armin, Levi and the remaining Warriors battled Eren and the shining centipede that originated all Titans, formerly nestled in the Founding Titan's spine. After making it inside Eren's Titan mouth thanks to assistance from Levi, Mikasa decapitated Eren's human body and kissed him goodbye for the first and last time. The final chapter confirms Eren's death -- for good this time. As the dust settles, Mikasa brings his head to Armin, who tearfully mourns his loss with her. She then leaves the battlefield with it, knowing a proper burial won't be afforded to Eren after the devastation he caused via The Rumbling.
As is the chapter's namesake, the final pages reveal -- three years later -- that Eren's gravesite is underneath the tree on Paradis Island he'd often napped under as a child. Mikasa tells him that their friends, Armin, Jean, Connie, Annie and Pieck, will soon arrive to visit him, along with Levi, Gabi, Falco and Onyankopon, presumably. Wistfully, she asks if he's happy before confessing she wants to meet him again.
As the words leave her mouth, the scarf Eren gave her when they first met slips from around her neck. To her surprise, a bird appears in front of her and ties it around her again. Smiling up at it as it continues its flight, she says, "Thank you for wrapping this scarf around me, Eren." Earlier, a similar-looking bird flew past Armin and the others on the ship bound for Paradis. The Scout unit used wings as its insignia and birds, in general, have been frequently used throughout the series as obvious symbols of what Eren longed for so desperately: freedom.
End of the Titan Age. Human life back to normal
Eren's endgame, all along, was to rid the world of Titans. The first few pages of the final chapter reveal the full conversation on this subject previously had between him and Armin via the Path -- when the Commander was still on the ship headed towards Eren's Wall Titan army. "You did it for the sake of the future you saw using the Attack Titan's power," Armin confirms, clearly referencing Eren's decision to kill 80 percent of humanity with the Rumbling. When Armin asks if he really needed to take things to that extreme, Eren shows him a vision of a volcanic, primordial land. According to him, "the power of the Titans continues to exist because Ymir has been obeying King Fritz for 2,000 years." Despite the violence the monarch committed against her village, parents and even her own body, shockingly, she truly loved Karl Fritz. It was this bond that kept her bound to him and his family for two millennia.
Eren says he doesn't fully understand her, but he did know she yearned to be free, waiting all this time for someone to "release her from the agony of love." Up until this point, we thought that person was Eren when he gained the full power of the Founding Titan from her. Instead, Eren reveals to Armin that that person was, in fact, Mikasa. That's why Ymir smiled at the end of Chapter #138 when Mikasa chose to kill Eren. Somehow, that choice liberated her, but only Ymir herself knows why. Once Eren and Armin's conversation is done in the Path, he erases Armin's memory of it, which Armin recovers in Chapter #139 after Eren dies.
Eren's death and Ymir's liberation by Mikasa also results in every Titan body turning to dust, and those that had been transformed restored back to human form. Knowing his sacrifice, Eren's friends are grateful for being relinquished from the Titan curse at last, but non-Eldians remain suspicious of them.
The meaning behind the ending of Attack on Titan
The chapter concludes with the previously stated three-year time jump, at which point the day the Rumbling was put an end has earned the moniker "Battle of Heaven and Earth." Even though the Titans are permanently gone, the Islanders are still worried about possible vengeance from the outside world. Under the Jeagerist flag, the military of the newly formed country of Eldia is established. Queen Historia, who is currently a mother of a three-year-old child, writes to Armin in a letter, "If we win, we live. We die if we lose. We can't prevail if you don't fight. Defend yourself. Until Eldia or the world vanishes, this battle will go on.. That is what Eren said, and he may be right. Even so, he chose to leave this world in our hands. This place we now live in. A world without Titans."
Armin, Reiner, Annie, Jean, Connie and Pieck are left to hope that upon their return to the Island -- having destroyed the walls and killed Eren, the Islanders' symbol of resistance -- they can broker a peace treaty as the Allied Nations' Ambassadors for Peace Talks. We never find out if they're successful or not, but Connie's faith in Historia and Armin's assurance that telling their side of the story will be enough ends things on a hopeful note for Attack on Titan.