The Ten Thousand Clans Invade, and I Become Humanity's Guardian

[Transmigration + School Life + Coming of Age + A Ridiculous, Treacherous System] Eighteen years ago, the myriad races invaded, leaving the world devastated. The Sword God appeared out of nowhere, wielding a sword alone to save a collapsing world and turn the tide at the brink of disaster, slaying a million demons. High school student Lu Yu transmigrates into this world and obtains a quest System. Completing its bizarre, infuriating tasks makes him stronger. Two years later, the myriad races are set to descend once more. This time, they swear to wipe out humanity. Lu Yu: “As humanity’s guardian, I shall purge the heavens and earth of all threats and secure a future for all people!” The Sword God: “Young man, the future is yours.”