Eliminated the Qing dynasty as the Taiping Heavenly Rebellion using Shi Dakai's sick leadership skills, simple enough. Yet when I westernized I was completely torn apart by the Xinhai Revolution, as all of China was carved up by various warlords. My population went from 112 million to 800,000. Of my once formidable army, only 36,000 loyalists remained - 9,000 stuck on Okinawa and 27,000 in Vietnam. Vietnam had been annexed by the Qing Empire for such time that multiple provinces were majority Chinese (mass emigration caused by the Yellow River flooding). But the situation was bloody dire; the capital had been lost, all of the provinces defected to warlords and the Heavenly dynasty was in danger of perishing.
There were numerous main players. In the southlands, Guangdong had 1,200,000 soldiers and an alliance with the Japanese. In the north, the Beiyang government had 4,500,000 soldiers. The other warlords averaged +800,000 soldiers. The neighbouring riverlander warlords had 900,000 troops each, but in the frenzy of reunification wars had declared war upon one another. This was my one and only chance to return Imperial rule to Tianjing, and so I declared war. I had two allies - Algeria and Brazil, who would take two years to arrive. The Japanese declared war upon me with Guangdong for the Okinawan islands. Even though the Heavenly Kingdom's Navy had remained loyal to me, and I would be able to keep the Japanese off of the islands with it - the Guangdongnese army was a world-ending threat so I gave up the islands without a fight.
The navy instead blockaded the riverland warlords whilst general Shi Dakai held the mountain passes & jungles outnumbered 10 to 1. I mobilised peasant forces to double my army and embarked on a bold march through the riverlands, even launching naval invasions to cut off the enemy troops from their capital. Despite such monumental victories it seemed overall success was impossible...
UNTIL THE BRAZILIAN ARTILLERY CORPS ARRIVED
What followed was a rapid march through the riverlands, striking fast against each one in rapid succession with a bare minimum force needed to seize the capitals and drive the warlords north. Once I had command of 27 million peoples I went to war with Guangdong, which at that point had pushed the Beiyang government north and commanded 2,400,000 men, versus my 560,000. this time unable to call upon the aid of the Brazilians or Algerians - Shi Dakai and the Heavenly Navy once more proved pivotal in cutting Guangdong in half. The war was quick, millions died, but the Taiping Heavenly Kingdom finally returned to Tianjing - moving the capital back to her homeland.
In the North, Chinese reunification rebels overtook the defeated warlords I had pushed back, all uniting under the Beiyang government. The Beiyang government itself fell to communist rebels, becoming the People's Republic of China. In the end, the PRC had 57,000,000 people to call upon whilst I had 52,000,000. The Japanese were busy invading Korea and the Russians & Brazilians were busy with the Ottoman Turks in the West. Within five months of the PRC unifying the North and heartlands and the Taiping unifying the Southlands and riverlands, we had a massive showdown which ended the same way it did with Guangdong - Shi Dakai and Deng Feng leading the charge, seizing the enemy's population centres before they could mobilize their forces in full.
In the aftermath of the war, significant warlords still remained, many with foreign protection. But with a population of 82,000,000, Taiping at last emerged as the Heavenly Hegemon of the China. In a few more years - the Hegemon of the East. Maybe in a few decades - the world.