Nankiti Tribe

The people of the Nankiti tribe live in and adjacent to a large floodplain nestled in a trio of sheer mountains. Their primary food source is fruits and grains from the field and fish from the river. One year, many centuries ago, the river flooded in greater volume than it ever had before and ever has since, in an event now known as "The Cursed Flood" or "The Black Moon." (It's rumored that the moon stayed a new moon for the entire month, but this is not true.) After the water receded enough to tend to the fields again (about a month later) life went on as normal for about a year. But then, they noticed a change that had been happening slowly. The tribe was getting sick. They were weak and always tired. The shamans quickly discovered that all of their food and water was now slightly toxic.
They tried every solution they could (prayer, magic, finding other food and drinking rain water) but to no avail. The poison was a magical curse on the whole land that the shaman's couldn't cure. And the surrounding terrain, combined with the tribe's lack of resources (such as wood) combined with their degraded physical health completely prevented them from leaving the valley. After several people started dying young, the shamans came up with one final last ditch effort. They devised a ritual where they created a new body and moved a sick person's soul into it (in essence reincarnating someone who was still alive.) 
 This worked, but had many unintended side effects. The new body was made to be an idealized version, but an otherwise exact replica, of the original, but the process wasn't perfect. Small changes in body size and proportion lead to people being uncoordinated, some were saddened about losing meaningful scars/birthmarks, changes in brain chemistry caused personality changes, etc. This caused a strangely ironic scenario akin to the inverse of actual reincarnation. The body looked nearly identical, but it was as if it was being inhabited by a slightly different person. At first, the process was being done almost constantly just to keep the tribe alive at all, but after enough attempts, the shamans learned how to make the new bodies resistant to the poison, and refined the technique so that the people kept their personalities. The process was also given the name, soulshifting.
Today the tribe is resistant enough to the curse that most only need a soulshift every 20 years or so, though the process has become a strong part of their culture, and is often performed more often than that. The tradition of moving to better, stronger bodies keeps the tribe strong and healthy, and a yearly cleansing ritual is performed that helps stave off some of the effects of the curse. The process also has another profound meaning to the tribe as well: A child's first soulshift marks his or her transition into adulthood.

Government

Shamanism

Defences

Mountains on all sides, all nearby food and water is poisonous to everyone other than the Nankiti, no one actually wants to go there.

Industry & Trade

Gathering and fishing.

Architecture

Grass-woven igloo-like structures.

Geography

Floodplain near a mountain stream in the bottom of a valley in the Sosoani Mountains.

Natural Resources

Berries, fruit trees, wild grains and seeds, fish, small mammals.

Type

Village

Location under

Sosoani Mountains