Falce

Also known as "Falce the Variablewand". When Falce is in her 'humanoid' form, she has the appearance of a tall, well endowned woman with a pair of spiraled horns on either side of her head. She has a very ditsy and naive personality. Despite this, she is incredibly powerful, able to use magic even when Suzuho is in her "Midnight Blue Vampire" form. She originally was the property of a powerful dark magician who died long ago leaving her alone. When Takuto stumped across her chamber during a training session, Falce took him captive. After fighting with Tanarotte and Suzuho, she was defeated. Later she returned, having accepted Takuto as her new master. In episode 4 she uses her powers to transform into many class related objects (mechanical pencil, etc). - Source: Wikipedia