His name is Ke Hai. This name has no meaning in this book. It is just a code name, because he is called Ke Hai in Ke Hai's world. This is a story full of contradictions.
Ke Hai was born in a slum. He met the Demon King when he was a teenager and followed him since then.
At the age of seventeen, Ke Hai became one of the guards around the Demon King.
At the age of eighteen, Ke Hai became one of the adjutants under the Demon King.
At the age of nineteen, Ke Hai became the Demon King's right-hand man.
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. When he was nineteen years old, Ke Hai performed a mission under the Demon King.
Intention: Intention to be added