Complex sentence: She is the self-proclaimed rival and traveling companion of Lina Inverse; while not a friend of Lina, she wasn't exactly an enemy, even though she often took sides opposite of the red-haired sorceress.
Split into simpler sentences: She is the self-proclaimed rival and traveling companion of Lina Inverse. While not a friend of Lina, she wasn't exactly an enemy, even though she often took sides opposite of the red-haired sorceress.