Sigyn is the 25-year-old Queen of Krisna. During military school she was known as the "Mad Scientist" for secluding herself in the school's lab for 3 days and nights without eating or drinking. While she is the Queen, she rarely acts like one and has instead pursued a career of science. She can usually be found with the royal engineers in the castle maintenance workshop tinkering with machines.

Sigyn cares deeply for her friends, to the point of pointing a gun at Rygart upon first seeing him to ask why he didn't show up at her wedding and confirm that he doesn't hate her. Even though she and Hodr are married, they do not share the same bed.