Catastrophe (Final Fantasy XIII)

Catastrophe, also known as the Day of Ragnarok from 0 AF onwards, is an important event that happened at the end of Final Fantasy XIII, and is a key event in its sequel, Final Fantasy XIII-2.

Datalog
Three years ago, mankind stared into the face of extinction when Cocoon almost crashed onto the surface of Pulse.

''The sphere's fall was halted by Lightning's companions, Fang and Vanille. Their desperate sacrifice summoned a massive pillar that cradled the plummeting Cocoon in its crystalline branches, averting an unimaginable disaster. The two l'Cie now sleep within the pillar in crystal form, and there are some who believe Lightning slumbers alongside them.''

A new age began from that day forth, with each subsequent year marked by the letters AF, or 'After the Fall.'

Final Fantasy XIII
When Lightning, Sazh Katzroy, Snow Villiers, Hope Estheim, Oerba Dia Vanille and Oerba Yun Fang defeated Orphan in its true form, Eden lost its power source with it and the Cocoon fal'Cie shutting down as Cocoon begins the rapid decent that the fal'Cie had been planning for. However, Vanille and Fang decided to become Ragnarok to prevent Cocoon's crash onto Pulse, encasing the sphere in crystal and forming a crystal pillar between it and Gran Pulse.

But their action, technically fulfilling their Focus, caused them to fall into crystal stasis within the pillar's core while Lightning, Snow Villiers, and Hope Estheim, and Sazh Katzroy were crystallized somewhere on the Archylte Steppe. But as revealed in Final Fantasy XIII-2, Etro bore witness to the Catastrophe and took pity on Lightning's group, restoring not only them but her sister Serah Farron and Sazh's son Dajh Katzroy. However, after she gave her blessing to Serah and Snow's marriage, Lightning was the first of many to suffer the consequences of Etro's intervention.

Final Fantasy XIII-2


As Etro intervened within the timeline, she caused the chaos from Valhalla to flood into Gran Pulse. Sucked into the Unseen Realm with most of the chaos, the rest seeped in the land's soil, Lightning was removed from that point in time. As a result, all but Serah believed Lightning to have died or sacrificed herself alongside Fang and Vanille. The event also caused a time disturbance that claimed the life of Paddra Nsu-Yeul and her various incarnations, causing her protector Caius Ballad to embark on his quest to destroy both Etro and reality. As for Fang and Vanille, they continued their role as Cocoon's pillar for 500 hundred years until they were safely removed prior to the structure's eventual destruction.

Trivia

 * The English name for one Noel Kreiss's downloadable content dual swords set is Catastrophe Blade, whereas the Japanese version calls it Calamity Blade.