Russia will become the savoir of the World, Russia is about to start its own path that will be separate to the western world. The special about Russian Culture is "Agony of Soul" that comes from Dostoevsky who was saint, not from Tolstoy who was a revolutionist (he spoke of Christ but he meant Marx) - "Tolstoy is the former Russia, Dostoevsky - the coming Russia", Russia will produce the new form of Christianity - without priests. New Russian Culture will be in opposition to the Faustian spirit, it is the spring of Russian Culture.
While Western civilization is coming to an end according to Spengler, Russia hadn't come even to a "Culture" stage yet, because from Peter the Great in 18 century when he destroyed tsarism, western culture was artificially implanted, the same happened in 19 century - Alexander I and the Holy Alliance in Paris, and then Bolshevist revolution also was motivated by western culture (Marx and money).
Spengler, Oswald, and Charles Francis Atkinson. 1926. The decline of the West. New York: A. A. Knopf.