Nina is one of the six main characters of the Six of Crows (2015) and Crooked Kingdom (2016) duology, as well as in the King of Scars (2019) and Rule of Wolves (2021) duology, all of which are written by author Leigh Bardugo as part of her "Grishaverse" collection of books.
When we meet Nina she is working as a Grisha Heartrender (someone who can magically manipulate a person’s blood flow, and consequently their emotions) for the Dregs, the street gang most of the main characters belong to. In fact she is incredibly talented with her ability, so much so multiple gangs have tried to recruit her. Unapologetically herself, Nina is loud, bold, flirtatious and also proudly plus-size, a rarity in YA fiction. Though she initially seems shameless, as the books go on, it is clear to the reader that Nina cares deeply about her loved ones and their opinions of her.
Throughout the books Nina is openly bi, and unashamed to discuss matters of the heart and her desires. In The Six of Crows Duology, her love interest is disgraced soldier Matthias Helvor — in a classic enemies to lovers, to enemies again, to lovers again, dynamic. In the spin-off King of Scars Duology, she has a new love interest, a non-binary, masculine presenting Grisha called Hanne.
Due to the alternative storyline in the Netflix adaptation Shadow and Bone, we have not yet seen much screen time of Nina so far. In the show (where she is portrayed by actress Danielle Galligan) Nina is described as a defector from the mainstream Grisha culture, who is loyal to her people, but not the government. Like her on-page counterpart, she too is a natural flirt, but clearly someone who loves deeply, and would do anything for those she loves. We will soon be seeing more of Nina in season two of Shadow and Bone.