WARNING: The following contains spoilers for Attack on Titan Season 4, Episode 24, "Pride," now streaming on Funimation, Hulu and Crunchyroll.
The world of Attack on Titan is changing dramatically now that Eren Jaeger has unleashed the Rumbling with the intent to wipe out all life. Old enemies and allies have returned and allegiances are being tested, and now an unthinkable alliance has formed. Nobody wants to see Eren use the Rumbling to destroy the world, which has forced the survivors of the Survey Corps to team up with the Marleyans who just invaded Paradis. As the last of the Colossus Titans moved off the island while Floch and the Jaegerists began rounding up any dissenters, it was time for a reunion of the 104th Cadet Training Corps.
Representing the Eldians of Paradis Island are Hange Zoë, Levi Ackermann, Mikasa Ackermann, Armin Arlert, Connie Springer and Jean Kirstein. The survivors of the Marleyan invasion, Theo Magath, Pieck Finger, Reiner Braun, Gabi Braun and Falco Grice, are also about to be reunited with their long-lost comrade Annie Leonhart. Zeke Jaeger's acolyte Yelena, as well as Anti-Marleyan Volunteer Onyankopon, have also been dragged into this ragtag mashup squad. Two Ackermanns, five of the Nine Titans, the best gunner in the Marleyan military and a handful of each nation's finest soldiers, this unlikely team might just be the world's best (and only) chance at survival.
For the Marleyans and Warriors who participated in the invasion, taking down Eren Jaeger was their plan anyway. Interestingly, despite the Marleyan faction making up almost half of the group, General Magath is the only actual Marleyan on Team "Stop Eren." As for Yelena, the shell-shocked woman is too distraught over Zeke's failure to be particularly interested in saving the world, but retrieving her was one of Magath's conditions for allying with the Scouts. Onyankopon has always been a staunch supporter of Eldians, but that doesn't mean he wants the entire world to be destroyed just to save them. The Anti-Marleyan Volunteer knows full well that his family in his homeland is doomed by the Rumbling if Eren is not stopped.
Annie, like Yelena, isn't overly interested in saving the world, but if that's what it takes to be reunited with her father, that's what she'll do. Reiner typically does whatever will most likely lead to his own death, which going after Eren nearly ensures. Despite having grown sympathetic for the filthy island devils, Gabi and Falco don't want to see the world destroyed, especially because their families in the Liberio Internment Zone will not be spared from the Rumbling. Pieck, Hange and Levi don't really have any love for Eren, and they know that his plan will only make things worse for Eldians should anyone survive his intended genocide.
Mikasa, Armin, Connie and Jean bear the heaviest burden of anyone in the group, as they each still care for Eren to various degrees. That even Mikasa and Armin have decided without much internal debate that they have to stop Eren speaks volumes for how far off the reservation their childhood friend has gone. If this group of former allies turned enemies turned allies again catches up to Eren, certain Marleyans in the group may have a bloodier resolution in mind than the Scouts prefer. A group hug or any team-building exercises feel highly unlikely, so this eclectic group of soldiers is almost certain to experience a significant amount of friction as they begin whatever their plan is to stop the Rumbling.
Nothing brings people together like the end of the world (in theory), so it's possible this group of enemies can put aside their differences for the greater good. Considering the number of Eldians that died on Paradis Island from the activation of the Rumbling, it's clear that Eren's plan doesn't actually benefit anyone other than himself. Eren's body as the Founding Titan is so gargantuan it makes the Colossus Titans look human-sized, so it's tough to say what even the power of the Nine Titans could do to stop him. The only thing that's certain is that the fate of the world of Attack on Titan is in the hands of this shaky new alliance between the Scouts and the Marleyans.