When we first meet her in Season 1 of "The Witcher," Yennefer is a deformed hunchback who is verbally and physically abused by her father, who eventually sells her to a sorceress named Tissaia de Vries (MyAna Buring). Tissaia brings Yennefer to study magic at the ancient school of Aretuza, where the neglected hunchback girl undergoes an agonizing transformation that requires her to sacrifice her fertility in exchange for great beauty.
In an interview with TheWrap, Anya Chalotra admitted that this transformation from a shy hunchback to a powerful sorceress was the biggest acting change of her career and that she could physically feel the shift in her performance due to the prosthetics she had to wear. "So before, I had the help of a back prosthetic and I had the jaw misalignment, so I had a mouthguard in my mouth. And all those things helped me and my movement," said Chalotra. "And then after transformation, I had the help of costumes and a corset and I felt a lot stronger."
Once again, Season 2 saw Yennefer undergoing another dramatic change in character and personality, having lost her ability to perform magic after using a forbidden fire spell at Sodden Hill. This is a new rock bottom for Yennefer, and in her hopeless desperation, she decides to sacrifice Ciri in order to regain her magical power. Thus, Season 2's Yennefer is presented as a wounded, wretched sorcerer who is willing to sacrifice the innocent in order to regain her power.
