Seth Balmore is one of the few immortals living in human form in the world of humans, where she has resided for over 1,000 years. She is a tough, fearless, and highly intelligent warrior, who is a valuable asset to the team. While at first she seems like a energetic, childish character, she is actually a smart, serious, and passionate person.
Seth has hardly any memories of the previous 1,000 years. As the story progresses, Seth gains back some of her memories, like the other immortals. The things we learn include her being a former pirate (famous at that), and that she has a son, Sed, also a famous pirate. When the two reunite, Sed looks old enough to be her grandfather, but since she's immortal, she looks the same as she has for all this time.
Seth wields heavy swords along with Kaim, and is the fastest and one of the strongest fighters in your party. Having been in the Uhran army, she has honed her battle skills, and can show them off impressively.