Adun

Adun was a Protoss character in the fictional StarCraft universe.

Very little is known about Adun, but the Protoss, especially the Templar Caste, revere him as a hero and even a demigod.

Adun and the Rogue Tribes
As the Aeon of Strife ended among the Protoss, the Khala was imposed on the entire race in an effort to prevent a return to the strife. However, a number of Protoss, fearful of the effects of the Khala, lived in secret on Aiur as Rogue Tribes, unknown to the majority of the Protoss. Only the Conclave knew of their existence.

Adun, an idealistic young warrior, was ordered by the Conclave to eradicate this threat, for reasons unknown. When Adun discovered these Rogue Tribes, however, he did not execute his orders. Instead, he tried to teach them how to use psionics without using the Khala. While he did successfully teach them how to hide themselves from the Conclave, his efforts to teach them the secrets of the psionic storm failed. Without the discipline of the Khala, their storms raged all over Aiur, alerting other Protoss of their existence.

The barely reunited tribes began to fight once more. Old vendettas and ancient prejudices were reborn as the Protoss who refused the way of Khala were branded as traitors and hunted down.

Eventually the Conclave devised a way to impose order on the Protoss once more. The Rogue Tribes were secretly placed on board a Xel'Naga Freighter and exiled from Aiur. Their fate was kept a secret from the other Protoss. Eventually they became known, in legend, as the Dark Templar.

Matriarch Raszagal, an old Protoss, is old enough to remember the exile, which caused much bitterness among her people.

Adun's actions afterwards are unknown.

Historical Accuracy
Raszagal, Matriarch of the Dark Templar, was 1,046 years old at the beginning of Brood War, and she was the only Dark Templar old enough to remember the exile from Aiur. This places the time of exile at about one thousand years before the beginning of StarCraft. As the oldest Protoss we are introduced to, it seems unlikely that any other Protoss could live three times as long as she has.

However, Taldarin, an old Protoss Dragoon, claims he and Adun fought side by side three thousand years ago, before Taldarin was crippled and placed into a Stasis Cell for "several millenia". He emerged in a life-preserving Dragoon.

Taldarin didn't claim to have accompanied Adun on the mission to pacify the Rogue Tribes. It is possible Adun himself spent time in stasis, for reasons unknown.