Crystal pillar (Final Fantasy XIII)

Crystal Pillar is a large crystal structure in Final Fantasy XIII and Final Fantasy XIII-2 that comes to support the body of Cocoon.

Story
At the end of Final Fantasy XIII Vanille and Fang transform into Ragnarok after the party defeats Orphan robbing Cocoon of its power source, sending the world of Cocoon plummeting toward Gran Pulse. Ragnarok crystallizes Cocoon's shell and builds a crystal pillar from the ground up to support the structure above the ground. Doing this, the duo crystallize themselves within the pillar and enter crystal stasis.

In Final Fantasy XIII-2 it is learned that the pillar holding Cocoon will eventually crumble sending the crystallized Cocoon plummeting to the surface of the planet, an event that marks the end of days to human civilization. A vision recorded by a Seerress is discovered in Yaschas Massif that shows the event where Cocoon comes crashing down after the Crystal Pillar has been destroyed. Serah Farron and Noel Kreiss set out to save the future, and after informing Hope Estheim in Yaschas Massif in 1X AF Hope sets it the Academy's mission to prepare for the event that is set to take place hundreds of years in the future.

Serah and Noel travel to Sunleth Waterscape in 300 AF where they find a giant flan eroding the Crystal Pillar and come to the conclusion that the flan would eventually weaken the crystal enough for it to send tremors on the ground making people nervous and eventually the panicking people would break into a war, which would culminate in the pillar's full destruction. Serah and Noel solve the paradox and defeat the flan.