H.N. Elly (the handle name for Kirsten) is a minor Witch villain from Puella Magi Madoka Magica. As every Witch, she used to be a magical girl until grief and despair overwhelmed her.
Official profile
"The box witch with a covetous nature. She is a staunchly reclusive witch. Anything she covets, she locks away within glass. The thoughts of her prisoners are laid bare, but one can strike her without thought without any problems."
Plot
H.N. Elly uses her Witch's Kiss to brainwash numerous people into starting a suicide cult as an attempt to ascend to heaven (in a manner similar to the Heaven's Gate religious movement). As she tries to stop the mass suicide, Madoka almost gets lynched by the brainwashed victims of the Witch, but gets swallowed into Elly's barrier at the last second. The witch uses mind reading to demoralize Madoka with images of Mami's death, but Sayaka, who has made a contract with Kyubey and become a magical girl, rescues her and slices the Witch to death with her sword.