Kir Xinn was born on Coruscant to Jedi Master Makirz Xinn and his wife. Kir was taught the ways of the Force by his father and teachers in the Jedi Temple there. At twelve Kir was taken as an apprentice and was taught in the Jed Temple on Tython. Kir was taught many things by his master. When Kir was twenty he met a Zeltron/Human woman named Shira Caz. They were married when Kir was twenty-eight. They had a son named Qyv.
A few years before Qyv was born Kir had started to collect and destroy Fire Force and Sith artifacts. After Qyv was born Kir started to look at the artifacts instead of destroying them. By the time Qyv was taken as an apprentice by Kir's niece, Kalna, Kir had become obsessed with the Fire Force. The Fire Force, Kir realized had been somewhat wrong in how they viewed their order. They had made it so that only Near-Humans could be members but there were a few members who had not been such as a the three fire Twi'leks and the Zabrak Lord of Fire. Kir wanted to be one of them so badly that he made a plan to leave the New Jedi Order and find out if the Fire Force was still in existence.
In 1,002 ABY Kir was assigned to a mission that he knew was going to fail. Shira went with him. The mission failed, and Kir, Shira, and the rest of the men and women who were with them were declared dead. But Kir had escaped and left to seek out the Fire Force. When he finally found them he found that it was not like it had originally been. The Dark Lord of Fire was a Twi'lek. By 1,009 ABY Kir killed the Lord of Fire and was named as Dark Lord of Fire because he had killed his predecessor.