Not much is known of Barjin's past. Once he was a member of an army in Vaasa under a powerful unknown leader (presumably Zhengyi, the Witch-King). Barjin dabbled in sorcery and necromancy and became quite efficient in each skill. Apparently, his leader became a god-like figure, and that is where Barjin first became a cleric. When his leader and his army fell, only he and a few of his soldiers survived. He claimed to have been visited by Talona's avatar, and it was she who led him to Castle Trinity. Barjin quickly rose in rank and became the leader of Castle Trinity's triumvirate. By this he also became Aballister Bonaduce's nemesis.
Barjin played a great role in Aballister's quest of releasing the Chaos Curse upon the Edificant Library. The Curse was a potion that brought people to fulfill their most private desires without caution to the consequences resulting thereof. When finished, Aballister named it "The Most Fatal Horror", a mock name of Barjin's title as a cleric of Talona. Barjin insisted that because of him being the leader of the Castle Trinity and a chosen of Talona, he himself should see about the release of the magic - alone. Barjin headed off with the curse, that has been put in an ever-smoking bottle, to affect anyone breathing the the mist. His first destination was the Edificant Library. Unfortunately, the bottle could only be opened by one of pure heart. But before finding a catalyst, Barjin had to worry about a way into the building itself. Mullivy, the library's groundskeeper, after being tortured, finally led Barjin into the catacombs of the library. This proved quite fortunate for the necromancer, who immediately started to raise undead guardians - starting with Mullivy, as his personal zombie guard, and ending with a mummy animated with the soul of one Khalif. Barjin found his catalyst for unleashing the Most Fatal Horror in the priest Cadderly Bonaduce who stumbled into Barjin's domain while sorting the bottles in the library's wine cellar. Somehow, Cadderly reached Barjin's altar room, and inadvertanly opened the bottle.
In the following days, the library slowly fell into chaos. Priests ate to obesity, others drank to insanity. Some of the library's inhabitants escaped the influence of the curse in one way or another: Cadderly Bonaduce, the dwarven brothers Ivan and Pikel Bouldershoulder, the monk Danica Maupoissant and the druid Newander. They went into the catacombs, battled hordes of skeletons, and tried to reach Barjin's altar room where they finally caught up with Barjin. Newander played the key role to Barjin's demise by disrupting the cleric's magical defenses, enabling his friends to finally kill Talona's desciple.