Marley launches a full-scale invasion of Paradis Island with the world's combined fleet, determined to crush the island before its Founding Titan can be used. Shiganshina becomes a battlefield once again as Marleyan forces and Survey Corps allies clash in a desperate struggle for survival. The Jaegerists, led by Floch Forster, seize political control of Paradis by staging a coup against Queen Historia's government. Zeke Yeager reveals his plan to euthanize all Eldians by using the Founding Titan's power to render them sterile, a twisted mercy he believes will end the cycle of hatred. Eren makes contact with Zeke in the Paths dimension and frees Ymir Fritz, the original Titan, from her two-thousand-year enslavement. The Rumbling is triggered as all the wall Titans awaken and begin their march across the ocean, marking the point of no return.
Marley's allied fleet arrives at the shores of Paradis, launching an amphibious assault that catches the island's defenders off guard despite advance warnings. The Jaegerists execute a coordinated uprising, overthrowing the military leadership and establishing Eren as the supreme authority of Paradis. Zeke and Eren meet in the Paths dimension, an endless space connecting all Subjects of Ymir across time and space, but Eren has been manipulating Zeke all along. Eren reveals that he has been controlling Grisha's actions in the past through the Attack Titan's ability to see future memories, meaning he orchestrated his own origin. Ymir Fritz chooses Eren over Zeke, granting him full access to the Founding Titan's power despite his non-royal bloodline. The wall Titans break free from their hardened shells, causing massive earthquakes across Paradis, and begin wading across the ocean toward Marley and the rest of the world.
This arc marks the moral turning point where Eren fully commits to global genocide as the solution to Paradis's survival problem. Zeke's euthanasia plan presents a morally complex alternative to Eren's total destruction, forcing a philosophical debate about the value of Eldian existence. The Paths dimension is fully explored, revealing the metaphysical mechanics of Titan power and Ymir Fritz's tragic history as a slave. Eren's manipulation of Grisha through time creates a tragic time loop that raises profound questions about free will versus destiny. The activation of the Rumbling represents the failure of diplomatic solutions and the triumph of the cycle of violence.