I personally see China and Russia forming a single superstate, like EU, at some point in the future. This will be good for both. China, with its positive population growth rate, needs to unload its workers - it needs land and materials. Russia, with its negative population growth rate, needs people to work in Siberia - there is plenty of land and resources, and not a single person for hundreds of miles. Even in the European part of Russia there are very few people left, most of them of retirement age, who can operate a lathe or a milling machine. (Same in the USA, by the way.)
“I personally see China and Russia forming a single superstate, like EU, at some point in the future. This will be good for both”
Win, win? Just ask the Tibetans what happens when a gazillion Han Chinese swarm over your land