The Game Invades the Earth

What was supposed to be a video game world filled with monsters and magical beings suddenly came true.
A huge tree more than ten thousand meters tall appeared near the beach with a portal inside its truck that churned out an endless horde of monsters and foul beings!

That was how the Great Calamity came to be.
Humans immediately band together as they realized a newfound power: an RPG-like system that allowed them to level up and cultivate their powers and that was how humans began to mount their comeback!