Deithwen loves Ciri – and that not just as a successful science experiment. She grew to know her a little bit when Avallac’h hid her for a little while in one of Deithwens secret gigantic Mansions when they were running from the Wild Hunt. Of course she was curious about her, as any Sage who worked on Elder Blood for hundreds of years would be, but witnessing her potential, her power and her fearlessness, made her overlook the shape of her ears, and it made her protect her against Eredin not just to further her own goals, or to save the fate of the universe. She protected her because (and she would never admit it, she’s too proud and too arrogant) she would be damned if she wouldn’t help her get to live the life she deserves under her watch.