Cleaver

The chapter opens years in the past, when a young Eren first approaches Armin after watching bullies leave him crying in a Shiganshina alley. The boy insists he never lost because he refused to flee, and Eren asks his name.

In the present, that same friend lies burned beyond recognition on a rooftop. Eren collapses beside the body, crediting Armin's thinking for bringing down Bertolt and wondering aloud why he never ran from anything. Zeke then descends into the district on the quadrupedal Titan and calls out to him. Holding a blade against Bertolt's throat, Eren identifies the newcomer as the Beast Titan, but freezes when Zeke claims the two of them are both Grisha's victims and that the man brainwashed his own son. The resemblance between Zeke and Grisha stuns him. Levi's appearance atop Wall Maria, soaked in Titan blood, cuts the exchange short, and Zeke retreats with a promise to one day return for Eren.

Across the district, Hange interrogates the limbless, blindfolded Reiner, who says the metal case he reached for holds a letter Ymir wrote for Historia. When he refuses to cooperate further, Hange moves to execute him, but Jean argues the Corps could claim his Titan power instead. Recalling Erwin's pre-battle briefing that only a single serum dose exists and must go to the most grievously wounded, Hange hesitates, then sends Mikasa to check on Eren with instructions to fire a flare if Reiner needs to die. Moments after the flare goes up, Zeke swoops in and carries Reiner off, nearly taking Hange's life in the process.

Eren begs Levi to spend the lone dose on Armin, who still draws faint breaths, so he can devour Bertolt and revive. Levi consents, until Floch staggers in with Erwin's ruined body across his back. Confirming the commander still breathes, the captain reverses himself, declaring the injection belongs to the man capable of saving humanity. Eren protests through tears, Mikasa draws her blade, and Zeke watches the standoff from the top of Wall Maria, telling Reiner how fortunate he is to be alive.

Zeke makes first contact with Eren, framing Grisha as a manipulator who victimized them both, and swears to come back for his half-brother.

Reiner reveals that Ymir left a letter meant for Historia shortly before Zeke and the Cart Titan pluck him out of Survey Corps custody.

Armin and Erwin both cling to life with a single serum dose available. Levi stuns the group by choosing Erwin over Armin, and Mikasa turns her blade on the captain as the chapter ends.

The Japanese title Ōnata plays on the idiom "wield the hatchet," an expression for taking drastic, sweeping action, which mirrors the brutal decision Levi faces. Before the volume release, the chapter circulated under the alternate title Falling Axe.

Volume 21 opens with this installment, the 83rd chapter of Hajime Isayama's manga, published in July 2016 as part of the Return to Shiganshina arc. Its events are adapted across the anime episodes Hero and Midnight Sun.