Putin saying USSR won WWII, he's not completely wrong.
It's not going to happen while he allows the hackers, scammers and blackmailers in his own country to wreak significant financial and physical damage to other countries via the Internet. It could be argued that he is waging a covert war against Europe.
Hitler's invasion of Russia was one of the greatest crimes in history in its execution, if not the greatest. It was the largest invasion in history, premised entirely on racism and genocide. And Russia was the one who paid an unimaginable to westerners blood toll to defeat this evil. Understanding that is crucial to understanding modern Russia, they haven't forgotten.
Germany Lost World War II because they were not strong enough to fight on two fronts. Putin's claim of winning the war is typical of his strong man persona. His claim is insulting to the other allied troops but he doesn't care.
Russia did take the brunt of the fighting & losses in WWII in Europe. As much as I'm not a fan of Soviet Russia, this fact is seldom acknowledged in Europe & the US.
Putin's claim that Russia deserves the lion's share of the credit for defeating Hitler is historically accurate. What is insulting is that most in the west are unaware of this.
They were also as despised as the Nazis in the countries they ransacked on their way to Germany.