Attack on Titan Season 4 Episode 21 Recap and Ending Explained

In the 21st episode of ‘Attack on Titan‘ season 4, Zeke ultimately comes to the realization that Eren has been manipulating their father by showing him only those memories that will eventually make him entrust his son with the power of the Titan and kill the Reiss family. The anti-hero manages even to convince Ymir to give him the Founding Titan so that he could shape the future of the world as he deems fit. As she finally ends her 2000 year long slavery of the royal family, Eren’s decapitated head transforms into the Founding Titan in the real world. Here is everything you need to know about the ending of ‘Attack on Titan’ season 4, episode 21. SPOILERS AHEAD!

Attack on Titan Season 4 Episode 21 Recap

After Grisha tells Zeke that he won’t get what he wants from now on and things will only go Eren’s way, the regretful father confesses that the future is full of suffering. Therefore, he asks his son to stop Eren, whose future memories terrify him. As the half-brothers return to the mysterious land surrounding the Coordinate, Zeke finally begins to fully connect the dots and realize how his brother used selective future memories to influence their father’s decision at the King of Wall’s Base.

Zeke wastes no time and asks Ymir to make her subjects infertile. Once the command is given, Ymir moves straight towards the Coordinate, but Eren frees himself from his chains, determined to stop her from carrying out the aforementioned orders. Two thousand years before the present-day events, Ymir’s village was captured and razed to the ground by the Eldians. The natives were then enslaved and treated harshly under the new king’s rule. One day when a few pigs escape from a pen and people blame Ymir for it; she is allowed to run so that she can then be hunted down by the Eldians as punishment.

Shortly afterward, Ymir is severely wounded and falls into a pool after entering a tree with a chasm. There she gets unknowingly fused with a mysterious spine-like creature and transforms into a Titan. However, she does not turn against the king despite the horrors that she has to suffer. As per his commands, Ymir crushes the Marleyans and helps the Eldians amass wealth and improve the infrastructure of the growing kingdom by building roads and bridges.

The king is so impressed by her dedication to the material advancement of his kingdom that he has children with her. However, 13 years after she acquires the power of Titan, Ymir dies, and her daughters Sina, Maria, and Rose eat their mother’s corpse. Ymir’s powers eventually get divided into nine Titans, who are then inherited by her subjects in the following centuries. Meanwhile, she continues to serve the royal family’s wishes in the Coordinate.

In the present time, when Eren catches up with Ymir, he begs her for her powers. He reminds her that she is neither a god nor an enslaved person but a human who has the choice to end the centuries-long pain and agony. Eren’s words touch Ymir, and she is moved to tears. Just moments later, the anti-hero is turned into the Founding Titan in the real world and starts the rumbling.

Attack on Titan Season 4 Episode 21 Ending: Why Did Eren Start the Rumbling?

The Marleyans have been determined to acquire the Founding Titan from the Eldians for their own military exploits for a long time. In the process, they also desire the extermination of the people living behind the walls whose ancestors have unleashed death and destruction on the rest of the world thousands of years ago. However, before they can manage to do that, Eren acquires the Founding Titan from his father, who in turn has stolen it from Frieda Reiss of the royal family.

In the following years, the Maryleans slowly begin to comprehend the nature of the threat that is looming over their heads. Therefore, they begin to make a move ahead of time, and Willy Tybur plays a crucial role in it. In a ceremony held with some of the most influential people from around the world, he openly speaks about the threat that Eren Yaeger poses and declares war on Paradis Island.

Eren, who has long-anticipated such a move, kills Willy just moments later and leads a surprise attack on Liberio with the assistance of the Survey Corps. It gives Eldians the much-needed time to regroup while the allied forces prepare to wage a war of extermination on Paradis Island. While Willy Tybur deliberately invites Eren’s wrath to compel other nations to join Marley in their war, the holder of the Founding Titan does not really have much choice.

Even if Tybur had not declared all-out war, the fate of the Eldians would have still been cruel as Marley and other nations would have probably continued to compete for the unused resources on the Paradis Island along with the powers of Titans. The subjects of Ymir would have been caught up in an endless cycle of war, and because of their primitive technologies, they would have eventually been cruelly wiped out.

While Zeke came up with the idea of the genetic neutering of the entire Eldian population to end the incessant bloodshed and war, Eren, who pretended to agree, was never on board with it. From a young age, the protagonist has fought back violently against anyone who has tried to trample his freedom, and even as an adult; he has not changed. So, to make sure that the outside world never kills another Eldian, he starts the rumbling so that he can crush every last enemy of the Paradis Island for good.

Read More: Why Did Grisha Yaeger Kill the Reiss Family in Attack on Titan?