River of the Pyreflies

The Pyreflies

In Spira, spiritual energy is something that can be seen and manipulated. It appears as small lights that emit a small sound. Because of the random and instinctual movements these lights make, they are called pyreflies, 幻光虫. Although mindless, pyreflies are attracted to several things and react to them, such as strong memories. Because of this phenomenon, pyreflies and water can be frozen into spheres, which can be used for recording and displaying such memories.

Pyreflies can also be manipulated to varying degrees. Aeons are made solid through the work of pyreflies. To an extreme degree, the armor of Sin is made by billions of pyreflies. When dreams such as Tidus and Jecht touched Sin, they came to 'life' because of the pyreflies.
Pyreflies in the Farplane

The Unsent

When someone doesn't accept their death, their pyreflies coalese into the form of monsters which attack the living. However, in rare cases an unsent person with a strong will can control their pyreflies and stay 'alive'. They would have the ability to sustain their shape using pyreflies and have the potential to exist forever, like Yunalesca.

The only way they can truly rest is if the Farplane Sendoff is performed, or if they willed it. This is why most of the unsent avoid the Farplane at Guadosalam, as they their will must be extremely powerful in order to retain themselves. Some also avoid Guados, who are capable of sensing if someone is unsent.
"No image of the living has ever been seen. It's a great mystery! But maybe... Maybe the dead leave a bit of themselves in the hearts of the living."
          –Maechen at Guadosalam
The pyreflies in the Farplane react to the memories of people who visit it. An Al Bhed theory is that after death, a part of everyone's soul becomes part of the living. This is why the pyreflies only show images of people who were sent, either by a Farplane Sendoff or by accepting their death.
The Farplane Jyscal leaving The Farplane

The Moonflow

A deep river called Moonflow, 幻光河, goes across the Djose Continent. Thousands of pyreflies are attracted to 幻光花, the Moon Lilies growing in it. This causes the river to give off an ethereal glow. It is through pyreflies interacting with the water that people in Spira can stay underwater for long periods of time.

Deep under the Moonflow lays an ancient city. The city was built on top of bridges during the golden age of Spira's history, when technology reached its peak. Yevon legend has it that the weight of the city caused the bridges to collapse, however it's more likely that Sin destroyed it. Since technology is now scarce, the most reliable way to cross the river is by riding Shoopuf.
Song of Prayer Princess Summoning End