He is the older brother to three sisters. In an accident he barely remembers, Gylfi's mother died, and in an attempt to save her, his father lost his leg. Gylfi's father would eventually find a new partner to bear three other children, all of whom Gylfi fiercely loves and protects.

Growing up in Indeholm, he was raised to hunt and care for Nordenstrekkers, though what truly called to him was the warrior's lifestyle. Wishing to follow in his father's footsteps, who was once a feared warrior with few equals, Gylfi dedicated much of his youth to training his swordsmanship, often earning him harsh disciplining when he skipped out on other responsibilities. He and Solveig Odasson had a primarily antagonistic relationship that carried into adulthood.