Item from Worm by Wildbow
Three kaiju-class threats that attack major population centers every few months — the existential sword hanging over every city on Earth Bet, including Brockton Bay.
The Endbringers are the reason the cape community exists in its current form. Behemoth, Leviathan, and the Simurgh — three entities of unknown origin that attack major cities on a rotating schedule, each one capable of killing hundreds of capes and destroying infrastructure on a metropolitan scale. They cannot be killed. They can only be driven off, and the cost of driving them off is measured in dead heroes and villains who set aside their differences for the duration of the fight. Brockton Bay has not been hit by an Endbringer. Yet. The city sits on the coast, which makes it a Leviathan target. The Protectorate runs Endbringer drills. The PRT maintains casualty projections. Every cape in the city knows that the truce protocols exist — when an Endbringer attacks, heroes and villains fight together, and all crimes committed during the battle are pardoned. It's the one thing everyone agrees on, because the alternative is extinction. The Endbringers are the background radiation of life on Earth Bet — a constant, low-level dread that shapes everything from city planning to cape recruitment to the willingness of villains to follow the unwritten rules. You don't fight Endbringers because you can win. You fight them because someone has to.
Also known as: Endbringers, the Endbringers, the Three