All Races Are Invading, I Am the Guardian Envoy of the Human Race

[Travel + Campus + Growth Flow + Pitfall System] Eighteen years ago, thousands of tribes invaded and all life was devastated. The sword god appeared out of nowhere, with one man and one sword, he could hold up the building before it collapsed, turn the tide before it fell, and kill millions of demons. High school student Lu Yu traveled through time and got the mission system. He could become stronger by completing weird and embarrassing missions. Two years later, all races will come again, and this time they vow to annihilate mankind. Lu Yu: "I am the guardian envoy of the human race. I want to destroy the heavens and establish a destiny for all people!" Sword God: "Young man, the future is yours."