I Am a Demon Slayer, How Could I Be the Demon King?

[The Demon King of the human camp] [The more I look like a demon, the harder I will kill the demon] My name is Fang Qi, and I am a demon slayer. At the same time, I fused the Demon Emperor Demon Pill, and I am also a Demon Emperor. They said that I was a traitor to humanity and that killing millions of monsters was just the way for me to return to the throne. Ha... What nonsense! I bleed for humanity! What beats in this body was never the demon heart! There is no way I can become a monster! ———— The spiritual energy revives, and everything mutates into demons. Fang Qi accidentally fused with the Demon Emperor Demon Pill, and swallowing the demon soul can increase the fusion degree. From then on, he embarked on the road of slaying demons and used the power of the Demon King to slay demons. With a fusion degree of 25%, he is rated as an F-level demon slayer. With a fusion degree of 75%, his body transformed into a demon and he tore apart an A-level demon with his hands. Until the fusion degree breaks through 100%, the power of the Demon King is fully revealed, and he is superior to all demons. Monster Management Bureau: "Fang Qi has always been our sharpest weapon against monsters!" Wan Yao: "He is a demon slayer, how can he have the power of the Demon King?!" Fang Qi: "Monsters, bow your heads! Your emperor is back!"