The Legendary Weapon from the Age of All-Purpose Mage and God

This is a magical world where human magicians and demons live together. After the demon cataclysm, the territory of the human kingdom was drastically reduced. The remaining humans migrated together and formed huge urban settlements. However, the demon empire is becoming more and more rampant, dormant outside the city, always ready to attack again. On this day, Qi Lan received a strange phone call in an ordinary rental house in Jingang City. "Hello, is this Zero Zero Seven?" "Yes, it's me, what do you need me to do?" "Kill someone for me." "Killing? I am a demon hunter, and I only deal with demon incidents. Shouldn't the killings be brought to the attention of the gang of desperadoes in the Killer Hall?" "In fact, the other party is not a complete person!" "Not a complete human being? What do you mean?"...