Yn

Yn are former humans who are transformed due to excessive exposure to jaki. They do not age, and cannot be harmed by regular human beings. Jaki is their source of power, and by attacking each other, they can absorb the jaki from other Yn, making themselves more powerful. Many Yn participate in the activity called the Melting Pot to thus increase their powers.

Most Yn look like horrid humanoid monsters, although some of the strongest of the Yn retain their human form with minimal changes. The non-human-form Yns fall into the following types:
 * Chaos Type (混沌タイプ)
 * Wanton Type (破戒タイプ)
 * Anarchy Type (混滅タイプ)
 * Irritation Type (焦燥タイプ)
 * Darkness Type (暗闇タイプ)
 * Destruction Type (滅亡タイプ)

The kanji of Yn literally means "Black", though it is pronounced like 陰 (Japanese way to pronounce "Ying" as in "Ying-Yang").