Conflicting accounts of the Zeison Sha place its foundation either circa 4,000 BBY and 2,000 BBY. The Zeison Sha are first mentioned in Wizards of the Coast’s Hero’s Guide supplement to their RPG, where they are referenced as having been formed by Republic colonists fleeing the devastation of the New Sith Wars. These travelers eventually settled on Yanibar but were forgotten by the Republic as their focus was diverted to the greater events in the galaxy.
As a result, the colonists were left to fend for themselves in the harsh conditions of this remote planet in Wild Space. Some of the colonists, whom were Force-sensitive, would go on to form the Zeison Sha, focusing their abilities around survival skills and telekinesis.
The Zeison Sha emphasized being independent and resourceful with their environment, but to also help meet the needs of others. Everyone was responsible to be efficient in survival techniques, but to also use these skills to help the community sustain itself. This reliance on self and one another fostered an attitude of independence from the Republic and the Jedi, whom the Zeison Sha and denizens of Yanibar came to view as abandoning them.
As a result of this distaste for the Republic and Jedi, the Zeison Sha developed a sense of unity in their organization and larger community. Children were not taken from their family like in the Jedi Order, but encouraged to maintain their family ties by living at home and commuting to their training at the temple, known as the Sha Kalan. Some training was even allowed at home, with a Zeison Sha tutor being supplied to Force-sensitive children with parents who were not Force-sensitive.
Along with augmenting their survival skills, the Zeison Sha became very proficient in telekinesis. They were skilled at using their surroundings to build a shield and then use those items as projectiles. Along with push, pull, levitate, crush, and smash, telekinesis became like second nature to many Zeison Sha. Their enhanced survival training provided members the ability to focus on performing these powers with unrivaled efficiency, even while under mental or physical duress.
Distancing themselves from the Jedi, the Zeison Sha chose to abandon the lightsaber as their primary weapon. Instead, they chose to wield a discblade, which was designed to aid them with their survival skills, as well as be an effective weapon for Force Throw. Experienced Zeison Sha warriors were able to imbue their discblade with the Force, augmenting its accuracy as a ranged weapon, or imbuing the blade to make it a stronger melee weapon.
To also aid in their defensive and survival prowess, members of the order would craft light armor, further augmenting their skills but with little to no reduction in mobility.
The Zeison Sha had a loose hierarchy, primarily divided up between initiates, warriors, and masters. It would seem the order did recognize the light side and dark side of the Force, though their order was more focused on independence, self-reliance, family and protecting the community. As a result, if members did fall to the dark side, they were hunted down and either converted back or eliminated.
As mentioned earlier, there is a discrepancy regarding the foundation of the Zeison Sha. Most sources point to circa 2,000 BBY, but the video game Knights of the Old Republic II: The Sith Lords provided countering information that they had formed as early as 4,000 BBY. Regardless, once the Sith threat was gone, members did re-enter the greater galaxy, but were disgusted at the Jedi’s practices, primarily when it came to children being removed from their families.
Travelling the galaxy again did peak the interest of the Jedi Order and in 580 BBY they sent Jedi Master Bodo Baas on a diplomatic mission in hopes of reunifying the Zeison Sha back into the order. The Jedi received a cold welcome, however, and soon ended the commission and departed Yanibar.
The Zeison Sha would continue to roam the galaxy into the rule of the Empire, however Yanibar did become occupied by Imperial forces, angering the planet’s denizens into armed resistance. Despite this denial of Imperial rule, the Zeison Sha did survive the Great Purge and the Yuuzhan Vong War; and though they disliked both the Vong and the Empire, they also secretly relished at the suffering both brought upon the Jedi.
It is unclear what became of the Zeison Sha following the Vong’s departure from the galaxy, but it could be assumed that their survival skills protected them from any quarrels with the Jedi, Imperial Knights, or Sith from Krayt’s order almost a century later.