Trag'Oul

"The guardian shall ever maintain his eternal watch over those who serve and protect the balance."

- Excerpt from the Books of Kalan

Trag'Oul (lit. The One Who is Forever, among other translations of the name) is an ancient and mysterious dragon-like being who guards Sanctuary and maintains the Balance between the High Heavens and the Burning Hells, intent on keeping Sanctuary free from angelic and demonic influences. His fate is tied to that of Sanctuary.

The Priests of Rathma use a five-sided pattern to represent Trag'Oul, the five points each holding a symbol representing one of the five elements they believe Trag'Oul to be linked to&mdash;earth, air, fire, water, and time. As the fulcrum of the Balance, they believe that the elements of Creation are tied to him.

Emergence
Trag'Oul entered Sanctuary for the first time just after the Purge by Lilith and Inarius's subsequent reactions. The dragon materialized for just a few seconds, long enough to lay the groundwork for Rathma's discovery of him. Trag'Oul was the first being to understand the Balance. From Trag'Oul, Rathma learnt of the Balance, the Worldstone, and how Sanctuary was created.

The Sin War
"This goes beyond Sanctuary now. Beyond all of us who stand sentinel." "How so? How can that be?" "Because the war is coming to Sanctuary, and if you interfere with what the Balance demands, it and all existence may be forfeit."

- The guardians and Trag'Oul in conversation

Trag'Oul tutored Mendeln during the Sin War. He believed that war on Sanctuary could devour all of existence if left unchecked. After learning of a pact between Inarius and Diablo, he tried to intervene, but was stopped by his fellow guardians that kept guard over worlds of their own. They warned him that inferference would risk all Creation. Fortunately, the Sin War ended, and Sanctuary was spared destruction.

Aftermath
Having founded the Priests of Rathma and set the Necromancers on their path, Trag'Oul vanished. He has not been seen since. The implications are dire, but the Priests of Rathma have not lost faith.

Diablo II
In Diablo II, the Necromancer set, Trang-Oul's Avatar, is the first mention of the dragon. Certain spells (Bone Spear, Teeth) draw upon his power.

Diablo III
Trag'Oul has no presence in Diablo III nor its expansion. However, there is an item named Trag'Oul Coils which are legendary bracers.

With the introduction of the class, more items appeared: the legendary scythe, Trag'Oul's Corroded Fang, and the Trag'Oul's Avatar set.

Diablo IV
On page adjacent to page 236 in The Art of Diablo Book, where Lilith can be seen holding Diablo's skull, at the bottom of the picture is displayed a serpent-like creature that is very reminiscent of Trag'Oul as he was depicted in the Book of Cain, hinting at his possible appearance in Diablo IV.

Personality and Traits
The Books of Kalan describe Trag'Oul as a celestial dragon whose body resembles a constellation of stars. In each of these stars, a different part of life is shown&mdash;past, present, and future choices to be made, so one cannot see a definite future. The Priests of Rathma believe that it is on Trag'Oul's back that the world lies, and is the closest thing the cult has to a deity. It is from Trag'Oul that Necromancers draw their power. It has also been suggested that he is a manifestation of the past, present, and future of humanity.

Trivia

 * Trag'Oul has undergone a spelling revision in Diablo lore. He was called Trang-Oul in Diablo II as in the set Trang-Oul's Avatar, and revised as Trag'oul in the Sin War novels. Since the novels are canon as of Diablo III, and as they were released after Diablo II, Trag'Oul is treated as the canon spelling.