Count Averin (Graf Averin)

The first book in a series about Count Averin's investigations.

Magical Petersburg, 1982.
Count Averin investigates the murder of a nobleman's son, which is blamed on divs, cruel magical creatures from the Wasteland. They obey humans but spiral out of control when they sense blood or weakness in their master.
Averin realizes this isn't the first murder and that a very powerful div is behind the crimes. Meanwhile, a huge demonic cat appears on Petrogradskaya Street...