Lux

Lux (ルクス) are particles of light that appear in Kingdom Hearts χ. They are gained by defeating Heartless and are used to rank players on a weekly basis, resulting in the availability of more prizes, which increase in rarity depending on how much Lux has been collected.

There are several factors that can influence the amount of Lux that is collectable. Every assist card the player uses increases the drop rate of Lux by a small amount; this depends upon the used assist card's level. Each day a number of "Lux Up Time" occur and while these periods last the amount of Lux earned when defeats Heartless automatically doubles.

The Lux determines all regular rankings in the game. All Lux collected during the week by Player sets their individual rank while the amount gathered by the whole Union sets the Union's place in return. The team that collects the most Lux during the day wins the daily team battle.

Kingdom Hearts X
The Lux was collected by many keyblade wielders from the five unions until the wielders broke into fight against each other over their Lux being stolen when unknown to them all it was the Nightmare Chirithy's doing. Do to the dream eater constantly seeing the wielders compete against each other for it, the nightmare thought if there was no Lux there would be no fighting.

Lux Lux