Board Thread:Lore Discussion/@comment-5983727-20130326234849/@comment-5737364-20130327000540

He is inquiring about what an event would require to be labeled the rank of crisis, such as the Oblivion Crisis or Dragon Crisis.

I would venture a guess that it is something like this, gathered from the dictionary definition of the word "crisis":

1. It must be a turning point, the trend for all events in the future will be determined here.

2. It must be a condition of danger, instability, or the like.

3. It may also be the point where a decisive change occurs, for good or for ill.