A True Nationalist respects other Nations, Putin does not respect Ukraine as a Nation.
There is no indication of that, I think.
Putin invaded Ukraine because NATO was seriously courting them to join. That would possibly put nuclear weapons on the Russian border.
Remember the Cuban Missile Crisis? That was our Ukraine. I think it is the same situation there.
Why should he they hate him and he knows that.
He fears them as a NATO member. With that, Russia would be wide open to attack, and ally Belarus encircled by NATO. This is suicidal for Putin, and he acted accordingly.
I think from his point of view he believes that he IS respecting a nation, the nation of Russia, which he believes includes Ukraine. He doesn’t see Ukraine as a separate nation, but as a Russian territory. Of course, the same could be said about China’s view of Taiwan, but I would say that China is very nationalistic as well, fiercely so.