I Have a Demon King's Castle!

Xiao Fei, who traveled to another world, actually owned a Demon King's City? And it's also bound to the strongest demon king system? When Xiao Fei showed off one breathtaking technical means after another, the whole world was amazed! "Is this really rice? Why does its growth cycle only last three days?" Xiao Fei: "Sorry, this is the devil rice I cultivated!" "How can you extract such pure table salt! What magic did you use?" Xiao Fei: "Sorry, this is knowledge. As for the method, it is confidential and will not be passed on to others!" Smelting metals, manufacturing firearms, industry. When Xiao Fei built his own army, there was only one name left in the world: Xiao Fei This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.