Here's a scenario that would make a great timeline.
In a alternate 1916, lets say Yuan Shikai manages gains foreign support and investments from Europeans in exchange on joining the war and sending troops to Europe.
After winning the National Protection War, Shikai assured the loyalty of his army by granting titles to his senior officers, promising that they would hold power in the new court. After securing his rule, he promptly dies. His son Yuan Keding becomes emperor, with his close fried, Wang Jingwei becomes Premier, which is the same as a prime minister. After the War, China regains it's former territories from Germany, and defeats most of the Northern Warlords and Tibet. During the Russian Civil War, the Chinese Empire retakes Out Manchuria. During Keding's reign, the Imperial Government successful modernize and industrialize the China in both military and Society, quell most Anti-Imperial opposition in the North, and began preparations on defensives near the Korean border, called the Manchurian Line, or the 'Asian Maginot' due to it being based on the Maginot Line in France.
The New Empire still has problems, like the Kuomintang in the South, still wanting to restore the republic, the impending Japanese Empire interest in becoming the sole Asian superpower, and a small clique of Chinese Communist between the two.

(This is not a complete map of the world, so ignore everything else except china. This is the best I can do)
Now given the scenario, here's a few questions:
Would the Japanese invade Manchuria still?
Would the Empire of China fall to fascism under Jingwei?
Which Asian power would Hitler pick? The Chinese or the Japanese?
How would the soviets react to the Empire of China
Would the Empire become imperialistic as Japan did?
Would China want Taiwan and Korea back?
Would a Chinese Civil war occur around the 1930s?
If a Second Sino-Japanese war occurs, what would be fighting?