A Demon King’s Life, Beginning in a Ruined Demon Castle

He transmigrated. Good news: he became the Demon King. Bad news: the Demon King's castle is a ruin, the previous Demon King choked to death on an apple, and for the new Demon King, even a slime could mean life or death. Fortunately, he has a talking Demon King's Book and has awakened the Demon King's exclusive ability: Monster Transmutation. So Mo Qiu turns cigarettes into smoking girls and treats everything around him as research material. Wait... Why are the Seven Demon Generals already watching me? Why has the Hero suddenly moved into the Demon King's castle? Why does the Demon King spend every day figuring out how to grow crops and feed the demon folk instead of conquering the world? And, Miss Hero, could you please take the holy sword away from my neck first? "Relax. I'm not going to kill you. Not yet." "Then why do you stare at me every day?" "Because I want to see whether you're really a Demon King or just a farmer." And so, beginning in a ruined castle, the new Demon King's strange life begins.