In the novel, Nadia is the one year younger partner of Swin in the Organization. Whereas graduating from Training School usually takes three to five years, Nadia proved to be gifted enough to complete her training in a single year. She's been working as an assassin under the alias of Nine of Swords alongside Swin for about a year now.
Swin's previous partner, Ace, is in fact her older brother. Swin hides this fact from her.
Nadia wields a needle from a stuffed toy and steel wires. She possesses a variety of needles, including several kinds of poisons, to adjust to the situation. She supports Swin's close combat by analysing the enemies and casting arts.