They've had the same mentality for hundreds of years. The problem is not that they believe themselves superior, also that they also believe in destroying the cultures they overrun and the Russification of everything. They've been killing Ukrainians for centuries for what they are. Or take the Circassian genocide where they reduced the population from 1.5m to 30-40K in a few years as a result of starvation and forced migration. Any neighbour not under their control is to be invaded and at the least, a puppet installed. Dudayev was precise in his 1995 analysis of how Russia would turn out post the collapse of the Soviet Union. Then they killed him...........
All this crap about denazification is complete bollocks. There are Nazis in every country on this planet - usually a small percentage. Problem with Russia is that they are in power in the Kremlin.
Hope springs eternal that one day they will make the connection between their actions and why only the likes of Trump and Orban think Putin is great. Then they can drag themselves into the 20th century.