Warning: This article contains spoilers for Witcher: Blood Origin.
Witcher: Blood Origin reveals an odd tie between Ciri and Geralt that makes the pair related. While Blood Origin released to mixed reviews, the series does serve a purpose for the greater series even for those who didn't enjoy the Witcher prequel spinoff. Not only does Blood Origin showcase more than one character who will be important in the future of the main Netflix Witcher show, it also provides a series of lore reveals that set up the future of the show.
However, the Witcher: Blood Origin show also seemingly has some more inadvertent twists in these reveals. This in no small part because of the scope of what the prequel has to explain - detailing the introduction of Chaos magic to the main Witcher world, how the Witchers themselves came to first be, and the geopolitical dynamic of the world prior to humans coming to the Continent, to name but a few major storylines. However, in explaining how Witchers came to be - and how the Elder Blood is linked to this transformation - Blood Origin makes Ciri and Geralt relatives, without ever directly referencing this particular detail.
Blood Origin's Ciri Elder Blood Reveal Makes Her A Geralt Relative
Witcher: Blood Origin explains that the Elder Blood that makes Ciri so powerful is ed down from her ancestors - Eíle and Fjall. This is especially notable because Fjall is the first person to successfully undergo a Witcher transformation, and it's suggested this plays a role in creating the Elder Blood line. While Witchers in the modern universe are sterile after undergoing the Trial of the Grasses and transforming, Fjall doesn't share this trait, and Eíle and Fjall's offspring as a result come from a post-transformation Witcher, meaning they inherit the monster genes Witchers are infused with.
Though the Witcher transformation process has changed somewhat by the time that Geralt undergoes the Trial of the Grasses, it appears to be the same in of infusing the subject with monster genes in order to enhance their fighting prowess. This means Geralt and Ciri share the same genes in this regard - which would make them relatives, albeit likely very distant ones. Stranger yet, this would make them related by sharing the same monster DNA - which is an especially unusual way to be related to someone even in the world of The Witcher.
Blood Origin Makes Geralt Even More Fated To Meet Ciri
Despite having very different upbringings, Geralt and Ciri's lives - and genetic makeup - both revolve around the exact same event: the creation of the first Witcher. Both are descendants of Blood Origin's Witcher transformation: Ciri being a descendant of Fjall directly, and Geralt being the last in a line of Witchers who followed in Fjall's footsteps. In this way, Ciri and Geralt's destinies were already intertwined before Geralt even claimed the Law of Surprise that would officially merge their fates. Though Witcher: Blood Origin had its flaws, bringing more parallels between the two most vital characters in The Witcher only makes their bond all the more poignant.