From Being Forced to Upgrade to Killing All the Demons in the World

Lu Jing traveled through time to a time of chaos and demons, but luckily he had a skill-adding system at his side. However, there seems to be something wrong with his point-adding system, so he can only add points first and pay them back later. Because a copy of "Ghost-Slaying Sword Technique" owed the system fifty years of life at the beginning, Lu Jing was forced to embark on the path of earning points by slaying demons. "What is this? Qigong training method? Let's see..." [Points have been advanced for you] [Please repay the double points after two months, otherwise they will be deducted from your lifespan] [Current points: -1000] "Who designed this retarded system!" ... Many years later, when Lu Jing broke through the netherworld and guarded the Demon Suppression Pass alone, he would still think of those days when he was forced to upgrade. [Current points: -999999....] How many more demons and monsters do I have to kill to pay off? Lu Jing sighed, put the long sword on his back, and continued on the long road regardless of the wails of thousands of demons and ghosts. "I'm sorry, I was really forced." This book is also called: "My point-adding system doesn't seem very smart"