Curse of the Ningyo

The Curse of the Ningyo was placed upon the Ningyo race by Ryujin, king of the Orochi. Ryujin, an ally of the Ningyo realized that the Ningyo are immortal. Also knowing that if other sentient races knew that a ningyo's immortality could be attained by eating a ningyo Ryujin cursed the Ningyo. The curse does not harm the Ningyo, however. Rather, any who eat a ningyo's flesh will become immortal, not needing to eat, drink of breathe, but will be cursed for all time. In addition, all Orochi can see invisible markings on these immortals and will not hesitate to take immediate vengeance.

Effects of the Curse
There are five curses total and one will randomly come to one who has eaten a Ningyo.

One cursed with the Curse of Air will only be able to confess his murder of the ningyo any time he tries to speak. Any time others speak to him all he hears is the wail of his victim.
 * The Curse of Air

One cursed with the Curse of Earth will turn into an immortal oak tree, forever rooted to the ground, yet with his mind intact.
 * The Curse of Earth

Instead of not needing to eat or drink, the person affected by the Curse of Fire is overtaken by burning hunger, yet cannot eat or drink normal food. A random substance will be the only food this person can ever have, and they must eat it at least once a day or immediately die.
 * The Curse of Fire

One cursed with the Curse of Void immediately turns into a hideous monster for all time.
 * The Curse of Void

One cursed with the Curse of Water becomes a ningyo, yet cannot breathe air and can only breathe underwater. Any orochi is able to tell if a ningyo is actually a cursed immortal and will immediately kill the individual.
 * The Curse of Water