Crisis Crossover

A Crisis Crossover is an in-universe crossover event that features characters from many different stories and brings them together to face a threat. It is a narrative tool intended to reset or change the status quo. While the concept dates back to Marvel's Secret Wars in 1984, it was DC's Crisis on Infinite Earths that became popular as it permanently defined and shaped their comic universe for years to come.

The scope of a Crisis Crossover is usually massive in scale, compared to trilogies or sagas, as it affects all characters within the fictional universe.

A modern example would be the MCU's Infinity War. The buildup was first established with the Space Stone, revealed to be within the Tesseract. The Guardians of the Galaxy introduced Thanos as the ultimate threat. In Infinity War, they discover Thanos wants to wipe out 50% of the universe. While comic book versions were motivated by a love interest, the MCU presents Thanos' goal as driven by personal gain.

Although typically used in comics for epic battles, due to its comic origins, the threat doesn't have to be direct for it to work. Stories inspired by or directly based on the COVID-19 Pandemic, such as Tony Bark's own NOVAR Crisis or South Park's 2-part Pandemic Special, technically count as Crisis-style events.