Can the emperor kill people at will?

The emperor also needs someone to protect him. If he kills indiscriminately, he is also worried that he has no protection. After all, the people who protect him are also afraid of being killed for no reason.

Children know that they have to find reasons to do bad things, let alone adults.

As for the reason, there is generally nothing to pay attention to, and it is generally ok. For example, when the Qing Dynasty entered the customs, Dourgen (not the emperor, but the regent at that time) ordered that "those above the wheel should be killed". Did it affect the Manchu occupation of the Central Plains? No, because they killed an alien, Yangzhou on the tenth, and so on, all of which were meritorious deeds. We just need to make our own people better.