UPS
The Justice League Almost Destroyed Reality with Three Words
Everyone knows that words have power, but in the DC Comics universe three single words spoken by Zatanna to Batman caused the dissolution of the Justice League, a major crisis, and came close to destroying all of reality. Identity Crisis, a famously controversial comics event from 2004, saw a major retcon take place in DC continuity that led to Batman descending into paranoid distrust, eventually leading to the event Infinite Crisis that very nearly saw the destruction of Earth and the entire Multiverse.