For 391 years, going from 794 to 1185, the real power in Japan was in the hands of the Fujiwara family (A option), they achieved that by monopolizing regent positions. The seize of power by abdicated emperors at the 11th century followed by the rise of the Samurais led to Fujiwara's gradual decline.
In the decline of Swedish influence and the emergence of Russia as a mojor power in that region
In Western Europe, the war was largely a stalemate as a result of extensive trench warfare that gave the defenders a massive advantage during battles. In Russia, however, the monarchy was overthrown by rebels, who then negotiated peace and surrendered large chunks of land to the Germans, allowing them to concentrate all their troops and resources to the Western Front.
