There's no way to know for sure without more information. It could be a group of soldiers if it's a military - themed story. They would be the ones carrying out the operation against the monsters.
I'm not sure specifically as it could be many things. It might be a military operation at night that involves some sort of monster - like in a fictional war scenario where the enemy is described as monsters. Or it could be a horror - themed story about a night - time operation to deal with real or supernatural monsters.
Some of the main characters could be Leon Kennedy. He is often a key figure in the story, known for his skills in combat and survival. Another might be Claire Redfield, a strong and resourceful character.
I'm not sure exactly, but it could be a brave hero who faces the monsters.
One of the main characters was Jozef Gabčík. He was an important figure in the operation.
The Tactical Dolls are the main characters. They are the ones who carry out the various operations.
Typically, the main characters are the various girl - like combat dolls in the Girl Frontline universe. Each with their own unique abilities and personalities.
I don't know the details of 'the monster story', so I can't say for sure. But it could be the monster itself as a main character, and maybe a human who crosses its path.
Since I don't know the specific 'operation finale novel', I can't say for sure who the main characters are.
I don't know the main characters in the 'knd operation novel' as I'm not familiar with this specific novel.
There are characters like Vector. He is a member of the Umbrella Security Service. And then there's Claire Redfield who is trying to survive and fight against the evil in Raccoon City.