Raan'losti

Raan'losti is an event the Vaanti believe to bring the end of the world. It was revealed to them by Your Character as The Endless, so that one day the Vaanti would help them defeat "The Hydra". In Chapter 14 of Book 2, it is revealed that Raan'losti happened the day they all left for La Huerta but in another dimension, hence why they weren't completely affected by it. Although it is why they saw yellow balls of lightning on the plane. By the start of Book 3, stopping Raan'losti from happening has become one of the main objectives of the Catalysts.

Mount Atropo
Mount Atropo is a volcano on La Huerta. On June 5th, there was an eruption which caused a ripple in time and space, creating different dimensions. This is why the people of Earth were affected and the characters on the plane weren't.