Special Operations Squad

Captain Levi Ackerman selects every member of the Special Operations Squad himself, prizing soldiers who act quickly and can stomach hard decisions. The original four, Eld Jinn, Oluo Bozado, Petra Ral, and Gunther Schultz, rank among the Survey Corps' deadliest Titan killers; their bond runs so deep that they coordinate attacks without a word or signal passing between them. After their deaths, Levi rebuilds the unit around the surviving top graduates of the 104th Training Corps together with Armin Arlert, and it endures until his retirement to Marley after the Battle of Heaven and Earth.

The first squad's charge is Eren Yeager. Its members supervise his Titan transformation experiments, and when a partial transformation erupts without warning over tea, they threaten him in a panic before apologizing by biting their own hands. On the 57th Expedition Outside the Walls the unit rides in the formation's most protected position, its true purpose being to lure the Female Titan into a restraining trap. The operation collapses: a disguised Annie Leonhart cuts down Gunther, transforms, and despite a superbly coordinated counterattack kills Eld, Petra, and Oluo one after another. Eren transforms to avenge them and is beaten, leaving Levi to pull him out.

The rebuilt squad shelters Eren and Historia Reiss in a remote cabin once her royal lineage surfaces, guarding both while Eren struggles to harden his Titan. When the pair become abduction targets, Jean Kirstein and Armin Arlert stand in as decoys, letting the squad trace the kidnappers to the Reeves Company and turn it into an ally. The plan to reach Rod Reiss unravels when Kenny Ackerman's Anti-Personnel Control Squad murders Dimo Reeves and pins it on the Corps. Hunted, the squad raids the Interior Military Police compound, learns where the captives are held, and storms the cavern beneath the Reiss chapel, where Eren's newfound hardening power saves them all from the collapsing roof. At Orvud District they help rig the explosives that blow apart Rod's colossal crawling Titan, and Historia lands the finishing cut herself before taking the crown.

At Shiganshina the squad faces the Armored and Colossus Titans at once. Under Armin's interim leadership, and later Jean's, they bait Reiner Braun into battle, blind and shatter his armor with Thunder Spears, and eventually cripple him so Mikasa can blast him from the nape, while Armin burns nearly to death in the gambit that lets Eren bring down Bertolt Hoover. Amid the aftermath, Levi spends the single Titan injection on the dying Armin rather than Erwin Smith. Months later the squad rides past Wall Maria on the Corps' first expedition beyond it in six years and stands together at the shoreline, the first people of the Walls to lay eyes on the ocean.

Levi Ackerman leads both incarnations as Squad Captain. The original roster consists of second-in-command Eld Jinn, Oluo Bozado, Petra Ral, and Gunther Schultz, all slain by the Female Titan. The second roster brings in Mikasa Ackerman, Armin Arlert, Jean Kirstein, Connie Springer, Sasha Blouse, Historia Reiss, and Eren Yeager; Historia steps away upon becoming queen, Sasha and ultimately Eren die in the conflict with Marley, and the unit dissolves with Levi's retirement.