A monarch rules the people. A king is merely a custodian. His job is to protect his people from being ruled over by inside and outside forces.
A monarch uses weapons of tyranny such as laws, police, army, courts, etc. A king needs none of it. His power is not obtained by granted. When I see patriotic Indians and Americans venerating their constitutions, I see Gollum saying “my precious”, as if all their freedoms come from the constitution. A constitution is merely a weapon of tyranny, which listens only to its master, the archetype of the tyrant.
A monarch rules via his law. A king merely tells it. He makes no law.
A monarch collects taxes to earn and establish his rule. A king collects no taxes. He only earns from tributes and from a daily job or trade. Perhaps, he is a farmer.
A monarch rules the people. A king is merely a custodian. His job is to protect his people from being ruled over by inside and outside forces. The former impose themselves on students. The latter is held up by the people.
A monarch must destroy morality to supplant it with legally. Since he can't control moral principles, he wants people to be guided by the law, which is a weapon of tyranny. A king frees his people from the law, for he is righteous. He guides them morally. He knows that freedom lies only in self-leadership and self-accountability to moral principles.
A monarch must suppress arts, humanities, and philosophy, for these disciples enlighten the mind of man. A king encourages the same disciplines. There where he lives, philosophers, saints, and poets are venerated.
People listen to the monarch because they have no choice. People listen to the king for his wisdom is high and pure. By his actions, he has never broken anyone’s trust. He has deceived no one. He tells the truth.
A monarch is like a parent who controls every aspect of his child’s life. A king intervenes only to stop him from eating mud.
When a monarch walks in the city, people look away because they are afraid of him. They don't like his rule. When a king walks in, people pay him legit respect. He is like Aragorn, son of Arathorn.
A monarch divides the land into smaller provinces to control the people. A king unifies the people. In fact, when people see him, they willingly submit to him. They want to be just like him. They want their children to be just like him. He is the ideal man to follow. He is the ideal leader. He is never chosen. He just is the king. People know it when they see him.
A monarch thinks that only great force can keep peril at bay. A king knows about the Dao. He controls nothing but merely intervenes. He never oversteps.
One example of a king is Krishna. He wasn't the ruler of Dwarika. Dwarika had no ruler. They called him Dwarikadheesh out of love. The same is true for Christ. He is never called the ruler/monarch of the Jews. He is called the king of jews.
PS. The face of Sauron is never shown in Lord of the Rings. And it can’t be shown. He has no face. Sauron is an archetype.