The Tyia was the religion of the Revwiens, a sentient, plant-like species from the planet Revyia, who worshiped the light side of the Force and taught of holding a high regard for peace and life. The Tyia was predominantly practiced by the Revwiens, to whom its ideals were very appealing.
While some sources claimed that the religion came to the planet as late as 30 BBY, Revwien Thuwistens had been seen across the galaxy for much of its history. Whenever they could, the Thuwistens spread the word of their beliefs to any who would listen.
At one point, Palpatine studied their methods in his quest to gain full mastery of the dark side.
In 19 BBY, the Tyia masters on Revyia were highly disturbed by the deaths of so many Jedi during the execution of Order 66 by the Galactic Empire at the end of the Clone Wars, which they could sense through the Force. The beginning of the Great Jedi Purge prompted them to call a meeting within a temple grown from the largest trees on their world. They then charged their most capable students with seeking out any surviving Jedi and aiding them in whatever way possible. One such Revwien Tyia adept was able to seek out and consult with a Human Jedi.
Tyia was a religion highly in tune with the light side of the Force. It taught that the value of peace and the sanctity of all life should be held above anything else. Its followers were expected to think and act honorably.
Tyia practitioners were known as Thuwisten, taking their name from the Tyia's prime tenet that one should seek "personal harmony with one's own Tyia so that other Tyia forces may join to form a bond-circle, a joining of spirits called 'Thuwisten', complete in their utter harmony." Indeed, Thuwisten believed that individual introspection was key to knowing the ways of the universe.
Tyia-practicing Force users were taught to control their personal Force through ceremony and meditation. Their focus on their inner Force resulted in Thuwisten having a heightened awareness of the skill the Jedi knew as "Control"; a Thuwisten found the use of the "Alter" ability to be a more difficult and time-consuming practice than the Jedi. Nonetheless, many Thuwisten regarded the Jedi as true masters of the Tyia.
- Star Wars: The Roleplaying Game, Second Edition
- Dark Empire Sourcebook
- Galaxy Guide 12: Aliens — Enemies and Allies
- Star Wars Gamemaster Screen, Revised
- Star Wars: The Roleplaying Game, Second Edition, Revised and Expanded
- Cracken's Threat Dossier
- Jedi Academy Training Manual