Demon Slayer Guard: Starting with Drawing My Blade

Just after celebrating his eighteenth birthday, Lin Yuan decides to give his body a special present: no staying up late tonight!

Instead, he somehow transmigrates to the Tang Dynasty.

He thinks his head full of modern knowledge will let him thrive in ancient times, but can someone explain this to him?

What kind of ancient people can knock down a whole mountain while fighting?!

And what is that giant roc blotting out the sky?!

And who is that young lady in red, breathing cold air against his neck at night?!!!