Answer: Kangxi emperor
Since the arrival of Matteo Ricci to China, the Jesuits used their excellent scientific training to be introduced to the Chinese ruling classes, reaching positions in the court of the emperor, and contributing to important developments in Chinese science.
So much so that the emperor of the Qing Dynasty, Kangxi, during his first years of reign approved the presence of the European Jesuits and their religion; publishing in 1692 an edict in which he praised the peaceful character of Christians and extended the protection of the court to temples dedicated to Christian worship.
However, from Europe Pope Clement XI did not agree with the religious syncretism between the practices of Christianity with Confucianism (which was considered a religion by the Pope). Which is why, in 1715, he published a document prohibiting Chinese Christians from participating in rituals of worship of ancestors and in many of the Confucian ritual forms.
Emperor Kangxi did not like the language used by the pope and considered him arrogant and disrespectful of his authority as emperor.
Consequently, on the year 1721, Emperor Kangxi published a decree forbidding Christian missions in China, stopping the expansion of Christianity in this country.