Item from Attack on Titan by Hajime Isayama
Millions of Colossal Titans within the walls, unleashed to trample the world flat. Eren activated it. The ultimate expression of the Founding Titan's power — genocide as geography.
The Rumbling is what happens when a wall becomes a weapon. For a hundred years, millions of Colossal Titans stood frozen inside the three walls of Paradis, shoulder to shoulder, a doomsday device hiding in plain sight. The First King built them as a deterrent — mutually assured destruction to keep the outside world from attacking. Eren Yeager used them as a sword. When he activated the Founding Titan's full power, the walls crumbled and the Colossal Titans within began to march. Across the ocean. Across continents. Flattening everything — cities, forests, mountains, people — under feet the size of buildings. The steam alone cooked everything within hundreds of meters. Eighty percent of humanity outside the walls was crushed. The Rumbling is not a battle. It is an extinction event with a heartbeat, driven by a boy who saw the ocean for the first time and felt only disappointment.
Also known as: the Rumbling, the global flattening, Eren's apocalypse