Halstein Valdissyn looks odd, even for someone of his short stature; he is completely hairless, with exaggerated musculature and grayish/stony skin. He is short but heavy, and has uncanny strength. His mother Valdis Jarðar Bonisagi arranged for him to be trained as custos, to serve her as a guardian.

He speaks Old Norse, Czech, and Latin, and resides in Turris Drekavatns.