Chief Sangster's decisions are made on the basis of two commitments. One, his position as Chief gives him guardianship of the village, but more importantly, of its people. Excluding his other commitment, everything he does is in the support of Sitheachdon's people.
Two, the Chief's position as sole parent of Laire makes him feel excessively responsible for her well being. This is a combination of pure fatherly love, grasping for the last remnants of his wife, and the will to extend his blood line. To this extent, he often puts Laire's well being ahead of his duties as chief, and is somewhat overly protective of her.
Chief Sangster is a selfless man, willingly putting the lives of people he barely knows before his own.
As a young man, Ulsar travelled throughout Terma, gaining experience in preparation for when he would be Chief. During a stop in a Fairlan town at the age of 26, he met the woman who would become his wife. By the time he was 28, a daughter had been born, named Laire Sangster.
At some point after Ulsar became chief, the woman left Sitheachdon, leaving him to care for Laire by himself.
By the time he was 47, Ulsar had become a respected chief, and generally a well-liked citizen. He helped to orchestrate responses to an appearance/attack by a Phoenix and the Dragon, Falgrn, but he was also quick to seek out Laire and assure her safety.