This is historically inaccurate and ideologically charged.
"During USSR" as you say, first wave of Russian immigration settled in West Berlin in 1920s running away from Russian revolution, so you probably did not mean that period of time. During occupation of Germany by Allies, both NATO and Warsaw Pact maintained significant military presence in Germany, but in 1990 Soviets have left (feel free to check it yourself in Karlshorst), Americans stayed. There was no migration of civilian Russians to Germany at that time, but DDR welcomed workers from other countries like Vietnam. Speaking of today, you can look at statistics on citizenship of Berlin residents: there you will find that, for example, more Indians than Russians are currently living in Berlin. And of course more Ukrainians.
There were a lot of people born in Russia with German ancestors and they had to leave Russia during WW2 or later left by themselves when the Soviet Union collapsed. Many chose to go back to Germany. This is also why there are probably a lot of Kazakhs in those statistics.
https://en.wikipedia.org/wiki/Russia_Germans
People are not servants of evil. What motivates this insane reasoning? As somebody with a German Citizenship I love my country and everybody who inhabits it.
to give context: remigration is a slogan held by far right parties in Germany with ties to neo-nazi movements. currently there are discussions to ban the most prominent, the AfD. remigration is most likely not a belief held by the majority of people living in Germany.
Reagan called the USSR an evil empire in 1983. I get the historical reference. I lived it.
800 years of Russian history has taught you nothing.