Blair is a cat with strong magical powers who was first mistaken for a witch by Maka and Soul. She was supposed to be the final soul they needed to make Soul a Death Scythe, but since Blair was not a witch they only took one of her nine "lives". Unfortunately, this meant that Maka and Soul had to start all over again from zero souls. After their fight, Blair moved in with Maka and Soul for no apparent reason and took up a part-time job in the Chuppa-cabras night club. Maka and Soul, as well as their friends, have quietly accepted Blair into their lives.
Blair's mantra "Pumpumkin-Pumkin" is said before using most of her powers, be it for aggressive, recreational, or personal interests. The theme of her magic consists of pumpkins, which she uses as weapons. She can launch pumpkins like cannon balls or pumpkin-shaped explosions. So far Blair has only demonstrated using her powers on inanimate objects. Blair is a skilled fighter and once single-handedly bested five Mizune witches during their assault on DWMA. Her cat form does not hamper her magical ability nor her ability to speak. In the manga, Blair has been shown to be strong enough to deal with the evil spirit The Flying Dutchman all by herself while in her cat form.
Blair is a bit naive and often refers to herself in third person. She is very good at understanding other people and is always looking for some fun whether it is harmless or not (although she is not without a conscience). Blair has started to take a liking to Soul (who she calls Scythe Boy). She uses her good looks to playfully flirt with him, usually by appearing out of her cat form in little to no clothing (implying she's a bit of an exhibitionist). Blair often does this to see Maka's reaction. In the manga, it is mentioned Blair's magic hat is named Zwan and she has an attack called "Smashing Pumpkin," both of which are references to the band of the same name. Blair's name may be a reference to the Blair Witch Project.