I suggest Civil War in Russia event.
During a severe instability (50% dis) Russia split into several parts.
Moscow and in the regions coming under the control of the rebels, calling themselves the Socialist Republic (Social Democrat)
They are at war with the federals, nationalists and fundamentalists. Can be supported by North Korea, China and Belarus. If they defeat federals, then Russia is renamed to Soviet Republic.
St. Petersburg and the nearby regions declare themselves Free Russia. This is nationalist forces (Autocrats)
They at war with the federals, socialists and fundamentalists. If they can win, then Russia is renamed to Russian Empire.
Siberian Republic (Social Conservative)
Capital is Novosibirsk. At the beginning is neutral to the other factions. Can be invaided by China.
Chechen Republic of Ichkeria (Fundamentalist)
In the Caucasus a lot of potential "freedom fighters", but Chechens the most influential. So they get all the northern Caucasus. Fight for independence and joining the Kuban. Supported by Saudi Arabia and other sunni fundamentalists.
Idel-Ural State (Fundamentalist)
Tatars revolted for independence. The capital - Kazan. Siberian Republic could try to capture them.
East Prussia (Social Liberal)
Kaliningrad declared independence. May request protection in Germany and become their puppet with subsequent integration.
Far Eastern Republic (Social Democrat)
Capital - Vladivostok. Includes Chukotka and Kamchatka. At the beginning is neutral to the other factions. The later can be joined by Siberian Republic, China (by force or asking protectorate) or become a puppet of Japan.