Miasma (term)

Miasma is a poisonous, aeriform substance, that plagues the world and sourrounds everything like air. It is the eternal threat of the people in Final Fantasy: Crystal Chronicles

Properties
The Miasma is pure poison. A single contact with it can cause death. Furthermore it is the substance, that is responsible for the appearance of the monsters. It is said, that long ago, there were no Miasma and no monsters.

The only way to keep the Miasma away is to remain inside the barrier of a crystal. The crystals in the world are protecting the people from the Miasma, but their power is not endless. Every year the crystals have to be cleaned by Myrrh, which is collected by the Crystal Caravans.

Origin (Spoiler!)
The Miasma is produced by the Meteo Parasite, in order to bring pain and suffering over the world, so that the memories of the people are focused of pain and suffering. That is, because Raem, who devours the memories of people, prefers this kind of memories.