Thunder Spear

Innovation inside the Walls was a crime for a century, but a few within the Military Police Brigade quietly preserved forbidden research records instead of destroying them. After the coup d'état, Hange Zoë hands those records to a team of engineers and the Thunder Spear is the result, an explosive projectile purpose-built to breach the Armored Titan and pair with the vertical maneuvering equipment. Hange demonstrates the prototype to Survey Corps soldiers by shattering a tree, and Eren Yeager dismissively dubs the devices "iron rods."

Early rigs mount one spear per arm plus reserves carried on the back. Four years of refinement push capacity to four per arm, eight in total, while multiplying destructive force: where two full volleys at Shiganshina only destroyed half of Reiner Braun's head, a single comparable wave at Liberio obliterates the Cart Titan and its Panzer Unit inside their metal shelter. A later firing mode even allows true ranged launches, the spear arming itself through its own momentum and holding detonation until it strikes a solid surface.

Each spear operates as a two-stage rocket. A trigger in the handle fires the initial charge, hurling the projectile with enough force to bury itself in hardened Titan hide. A cord tethers the projectile to the launch unit; when that line severs, a safety pin pulls free and the second charge detonates, driving the warhead deeper in a massive blast. The fuse delay is almost nothing, yet just long enough for a soldier on maneuvering gear to swing clear.

The weapon cuts both ways. Its blast radius endangers the wielder, making it practical only where nearby structures allow an instant retreat on the wires; caught in the open, a user risks being consumed by their own explosion. Though designed for one specific enemy, it devastates ordinary Titans as well, and a single spear can shear off the Female Titan's arm. The Corps also discovers a grimmer application: a primed spear placed inside a captive shifter, fuse looped around the throat, threatens damage beyond even Titan regeneration. Levi Ackerman restrains Zeke Yeager this way, though Zeke chooses to detonate it anyway, catching Levi in the blast and surviving the point-blank explosion himself.

Effective use demands drilled coordination. For the Armored Titan, Hange scripts a three-wave sequence, blinding the target first, cracking the shell second, killing third, and positions Squad Levi precisely despite minimal training time. In the following years the wider Corps trains extensively in solo and team tactics with the weapon.

The spears see first combat at the Battle of Shiganshina District as the Fourth Squad and Special Operations Squad swarm the Armored Titan and blast open its nape; Reiner survives only by shifting his consciousness into his nervous system. Mikasa Ackerman's attempt on the Colossus Titan fares worse, as a wall of superheated steam cooks off her spears mid-flight and peppers her with shrapnel. The squad's last four spears finish Reiner regardless: Mikasa cripples the Armored Titan's leg, Sasha, Connie, and a returning Hange wreck its jaw, and Mikasa's final shot through the open mouth blows Reiner clean out of the nape.

At the Raid on Liberio the weapon anchors the Corps' urban assault, demolishing anti-Titan artillery emplacements, screening Eren from the Jaw Titan, and battering the War Hammer Titan, whose remote pilot and crystal casing frustrate even massed spear barrages until other means finish the fight. In the War for Paradis, Levi uses several to burst the Beast Titan's hardened nape, the Yeagerists arm themselves with captured stocks to hold the island's port, and Hange spends their final moments spearing two Wall Titans at Odiha to buy time for the flying boat. The last reserves fly at the Battle of Heaven and Earth, turned by Armin Arlert's survivors against the horde of resurrected past Nine Titans summoned by Eren. Creator Hajime Isayama traces the weapon's inspiration to the bottle rockets he played with as a boy.