What Does It Mean That I Am One of the Three Hundred Demon King Candidates?

You said that every thousand years, the demon world will hold a demon king election, open a channel with the human world and send a hundred monsters to the human world? Huh, what a fantasy! There were images from 20 years ago that were classified as top secret in the military? Okay, but it's said to be every thousand years, and the last one just ended, so it doesn't affect my job as a hunter to make money. What does it mean that the benevolent king and his companions disappeared for ten years, and this time they sent 300 monsters to the human world to select the acting demon king again? I don't want to be the monster's heart partner, and I don't want to be a target in a battle between monsters. If there are no monsters that can communicate with me, then that's fine. As long as my mission target doesn't have any monster companions to control him, I'll fight him to death. Wait, what does it mean that I am one of the three hundred demon king candidates?