What is your point?
Do you want to say that Mongolian Emperor, Genghis Khan, who ruled China and established the Yuan Dynasty in China, is a Chinese?
If so, I admit it is weird.
First of all, what is "Chinese" and "China"?
China (中國/ 中華/ the Middle Land) has official become a country name since the Republic was formed,
before that there was not a country named "China", same story with India and Germany.
Don't you think that the Emperors of Mughal Empire are Indians?
Don't you think that Alexandria the Great, who established the Macedonia Empire, is a Greece?
Don't you think that Bismarck, the Eiserner Kanzler from Prussia who established German Empire, is a German?
Besides, Japan, Korea and Vietnam used to called themselves "China" (中國/ 中華/ the Middle Land), were they not?
as for "Chinese", same as "Vietnamese", which is a huge ethnic groups mixed with lots of different ethnics.
Since China is a nation established by Chinese ethnics including Manchurian, Han, Mongolian, Hui, Tibetans etc. Why do you think that the Yuan Dynasty, established by Mongolian, is not belong to China?