Attack on Titan's latest arc in the manga has been building toward a endgame that fans had no idea would be coming when the series first began. This definitely includes the many changes to Eren since the series' time jump.
Eren's been distancing himself from Mikasa for a long time, but Chapter 112 of the series completely shook their relationship apart as Eren tells Mikasa he's always hated her.
Mikasa and Eren have been friends since they were children, and they had been especially close after Eren and Mikasa survived a deadly and traumatic experience together. But Eren's been weird since the time jump and his time spent hidden away in Marley. He's fully gone rogue after his attack on Marley, even forming a new revolutionary faction.
With this, Eren thinks he's completely different before and revealed a new outlook on Mikasa. The Ackermanns were apparently created to be a vessel that can activate the Power of the Titans but retain their human form. Eren claims they were made to protect Eldia's kings and their clan will automatically protect their host through instinct.
Eren says that when Mikasa activated her own inner strength, she ceased to be Mikasa and became a slave to her genes. Eren says as a result, he has hated Mikasa since childhood because she's not "free" in his eyes.
As a result, Armin and Eren get into a fistfight and this blows up their entire friendship completely. No one knows what's going through Eren's head at this time, and clearly it's not going to be a completely peaceful resolution when it's all said and done. Hard to walk back something like this.
Attack on Titan was originally created by Hajime Isayama, and the series has since been collected into 23 volumes as of 2017. It's set in a world where the last remnants of humanity live within a walled city in order to escape the danger of the Titans, a race of giants monsters that eats humans. The lead character, Eren Yeager, ends up joining the military with his two childhood friends Mikasa and Armin after the Titans break through the wall and attack his hometown.
Now Eren, Mikasa, and Armin must survive in a world where they not only have the Titans to fear, but the very humans they are trying to save. You can currently find the series streaming on Crunchyroll, Funimation, and Saturday nights on Adult Swim's Toonami block. The series has also been confirmed for a live-action adaptation produced by Warner Bros. and directed by IT director Andy Muschietti.
If you are curious about how the series may end, series creator Hajime Isayama recently revealed the final page of the manga, meaning that not only is the endgame of the series nearing than ever there's a concrete ending in mind.