Unlike traditional "good vs. evil" stories, the Watches are bound by a Great Treaty . The Light can be bureaucratic and cold, while the Dark emphasizes individual freedom. This "gray area" makes the protagonist Anton Gorodetsky’s internal struggles deeply engaging.
The series began in 1998 with Night Watch and has since expanded into a multi-book saga, including major films and video games. It centers on the "Others"—humans with supernatural abilities (vampires, mages, shapeshifters) who are divided into two factions: the (Night Watch) and the Dark (Day Watch). Review of the "Dozor" Series
The series of books you are referring to is the (Watch) series by Sergei Lukyanenko , a cornerstone of modern Russian urban fantasy. Series Overview