Magic and combat
The practice of martial arts does more for Hong Gildong than just add physical strength and confidence. The novel also includes depictions of magic powers that Gildong unlocks in himself through discipline and excellence. He is a chosen one in some senses, because his ability to fight makes him an automatic candidate for a hero's journey. His magical fighting is clearly the stuff of legend.
The hero's journey
Hong Gildong realizes that at his family home, he is merely awaiting assassins who don't want him alive. After a fight against would-be assassins, he leaves the palace to see what other places might have to offer him. He is on a hero's journey, and the depiction of that cycle is clearly at the center of the novel's meaning. He leaves his home because of an inciting incident and journeys into the unknown, finding a community in the underworld.
Crime and the underworld
Some heroes struggle to find their power, and many heroes find their power along the way in the hero's journey, but Hong Gildong is a magical warrior from the start, so when he enters the archetypal domain of the underground, the criminal element of his community, he rises to the top. By reading the imagery, Gildong can be seen as a king of the underworld. He gives money to the poor which only helps him rise even higher than he could have otherwise, as a Robin Hood type figure.
The rise of government
If Part One is about Hong Gildong's early life, and Part Two is his hero's journey into the underworld of life, detailing his rise to power and fame, then what does Part Three offer the story? Well, for one, it offers the tangible imagery of Gildong's rise from gang overlord to actual kingship. He establishes a gang that quickly organizes a government in the land of Yul, and the people of Yul accept him as the king because of his competence. The story details the rise of a king from start to finish.
