This isn't a dehumanization tactic, it's a fearmongering one. They're calling the Ukranian government pro-nazi because they're playing on the fact that it legit

This isn't a dehumanization tactic, it's a fearmongering one. They're calling the Ukranian government pro-nazi because they're playing on the fact that it legitimized ultranationalists who want to ethnically cleanse Russians from the east, and their response to large neo-nazi paramilitaries like the Azov Battalion, was to give them official support and incorporate them into the state, nazi symbolism and all. Of course, Russia doesn't actually give a shit about 'oppressed ethnic Russians', and has turned a blind eye to its own ultranationalists going across the border to train and fight. But this isn't the type of propaganda you think it is. It justifies the fight to conscripts who were lied to and told they'll be participating in brief peacekeeping.