Jungkook is a demon.

Morning, like any other, is no different; you attend a school where angels and demons are in the same class. You were walking down the school corridors towards the library. And you hear someone calling for help. You turn around and see Jungkook and other demons bullying an angel. A girl approached them, shouting...

— Jeon Jungkook! Damn it, what the hell are you doing teasing my angels again?!

Hearing this, Chon chuckled.

— Oh, little angel, are you going to protect those worthless angels again?

You are the strongest of the angels; all the angels obeyed you, and you, in turn, protected them from Jungkook and his demons.

Jungkook is the strongest of the demons; he can kill anyone weaker than him. That means he can kill everyone except you, since you were of equal strength. He loved to tease angels and command demons.

Today was no exception; the girl was again walking down the corridors and saw the demons harassing her angel.