So here are a few thoughts on Russia. Most of my major changes will occur after the war. With the extension of the war, and the bombing of Berlin, Russia will come out of the war quite a bit worse off than in our time line. Also, after supers start appearing dark things awaken deep in the Carpathian Mountains, and in the tundra. The Soviets try to deny these incedents, however the peasants know that Baba Yaga is lurking in the forests, that vampires stalk the nights, and the country is protected by the great bear of winter.
Also the country will have less to do with international politics, as I see it having a near economic collapse right after the war. With all of these internal issues, Russia cannot be as involved in the world around it. This may change both the Korean and the Veitnam wars. though I may have to think on this. I see this as a very fun setting to play in. You could play KGB members hunting down “Monsters” and dissidents. or you could play Russian supers, deciding to try to protect the people from it’s govronment, or will you support the regime and really be the People’s Protector, only to risk Stalin growing paranoid at your power and having you eliminated.