Is there a way to prevent Vesemir death?
No,
you can't save Vasemir, he die by default.
Who was Geralt's father?
Korin
Martin Berencsy will be The
Witcher's Korin. The only Korin known of in the books happens to be Geralt's father. Korin appears in just one short story in the entire saga: A Road With No Return.
Who is Ciri's parents Witcher?
Ciri's parents are
Duny, the Urcheon of Erlenwald (Bart Edwards) and Pavetta of Cintra (Gaia Mondadori). During a betrothal ceremony to pick a partner to marry Pavetta, Duny interrupts the ceremony to declare his love for her.