Emperor Kangxi was talented and studious since he was a child. He is not only familiar with Manchu and Chinese, but also knows poetry and songs like the back of his hand. He is such a man with both civil and military skills, but he has not educated his children well. I don't think it's entirely the fault of Kangxi, because he was a king first, and then a father. Sometimes he has to make some sacrifices for the stability of Jiangshan design and fundraising.
For example, he attached great importance to the throwing of Prince Yin, and made him the Crown Prince at birth. He loved this son very much since he was a child and taught him carefully, hoping to train the prince into a qualified successor and become another emperor through the ages. But perhaps because he was too spoiled, the prince became more and more arrogant as an adult. Even after Kangxi got older, the prince became disloyal. During Kangxi's southern tour, the prince sent his men to inquire about Kangxi's diet and daily life.
So Kangxi was disappointed with the prince. In order to ensure that the country can be handed over to a truly talented person, Kangxi had to make up his mind to abolish the prince and make another will. However, after the abolition of the Prince, Kangxi was slow to make a decision, which led to the appointment of the Nine Kings in his later years.
Kangxi was also cruel to his daughter. His beloved Princess Rong Fei gave birth to their only daughter, Princess Lanqier. However, in order to pacify the country, Kangxi married his daughter to Zhungeer tribe, but finally personally killed his son-in-law and relegated Rong Fei to the cold palace.