This may require some suspense of disbelief, but let's say Tsarist Russia survives WW I by the hair on its teeth and is present at Versailles. Russia gets Galicia and Bukovina from Austria-Hungary and perhaps Posen from Germany. We'll leave the other details of the ATL Versailles aside for the sake of the discussion.
Now, IOTL, the fledgling USSR supported the Kuomintang from the early 1920s onward, but I can't see a Tsarist Russia doing that. Russia wants to establish a sphere of influence in northern China. Supporting an openly nationalist, revolutionary government isn't the obvious move here. The only way that would happen would be a marriage of convenience under the slogan "the enemy of my enemy is my friend", that enemy being Japan, which has its own designs on China. I could see Russia wanting to address old grievances left from the Russo-Japanese War, possibly leading to a second RJW in the 1920s or 30s.
So, if not for the KMT, who becomes St. Petersburg's proxy in Warlord Era China? Would it be one or the other warlord or a clique of them? Or would Russia be more direct and use a Qing restoration as a façade for Russian control, like Japan did IOTL?