Varania is a Tevinter elven mage and Fenris' sister. He's a minor antagonist in Dragon Age II, because she tried to help Fenris' former master, Danarius to recapture him, so that she could become his pupil and a magister.
Danarius' apprentice, Hadriana, tells Fenris during his personal quest that he has a sister and offers more detailed information in exchange for her life. Fenris, whose memories of his pre-slave life have been erased by Danarius, will accept the deal but kill Hadriana anyway. He is told that his sister, Varania, is still in Tevinter and serves at the court of Magister Ahriman. When Fenris asks if she is a Slavery, Hadriana denies that and tells him Varania is a servant. Unbeknown to Fenris, she is also a mage trying to be taken into apprenticeship with one of the Tevinter Magisters. Varania and Fenris grew up together in Tevinter, however Fenris does not remember.
Varania is used to lure Fenris into a trap set by his former master Danarius. The magister promised her that if she would help him capture her brother, he would make her his apprentice. Fenris can either kill her or let her go.