Top-Tier Mecha Sign-In from the Start: I Invade the Land of the Behemoths

In 2038, giant beasts invaded Earth. Humanity was utterly powerless against their relentless attacks. With no other choice, people built enormous stone walls, which barely allowed them to live in peace. But that didn't last long. Two years later, the giant beasts breached the walls. Just then, Ling Yun awakened the top-tier Mecha Sign-In System...

"Host Ling Yun, verifying identity. Verification successful!"

"Host! Congratulations, you've signed in successfully and obtained a first-tier mecha, the Doomsday Crisis. Would you like to summon it now?"

This novel and its characters are entirely fictional. Any resemblance to actual people or events is purely coincidental. Do not imitate.