It would be helpful to know more details of this person’s history before branding him a Nazi. Given that Ukraine lost millions of people to Soviet terror and engineered famine between 1920 and 1940, it is not surprising that the German invasion was welcomed by some. They had to pick a side. Nazi’s or Reds? If this person was complicit in the murder of Jews then calling him a Nazi is fair. If he just hated Russians it is not.
The current Ukrainian army, Azov Battalions, are all Nazis, as is Zelenski.
The Azov’s were committing genocide in the Donetsk on the Russian speaking peoples.