In 3050, Humanity Devolves, but I’m Invincible

[Decisive and ruthless + Invincible + Original worldbuilding + Satisfying]

A global nuclear war led my country to put me in cryogenic storage. All of humanity went underground, while most of the surface became desert, and even a forbidden zone for mankind.

A thousand years later, I unexpectedly woke from cryogenic sleep.

I discovered that the world had regressed terribly, and Dragon Country had become a place where anyone could bully its people.

I also found that humans were even more fragile than college students!

They weighed only around ten pounds, and most were barely five feet tall.

But all sorts of strange beasts had appeared.

Rats as big as large dogs, “phoenixes,” and even dragons.

Su Hao was invincible in this world. He became the founding ancestor of Dragon Country and led it back to greatness.

I lifted a ten-kilogram dumbbell. “Ancestor, how are you so strong? You're truly comparable to the ancient gods!”

I opened the door and felt the 20-degree air outside.

“Ancestor, h-how can you stand such bitter cold?”

I wanted to take a stroll in the park.

“Ancestor, you absolutely mustn't go there. Demonic beasts have been spotted in that area.”

I tamed a stray dog.

“Ancestor, you're amazing. Even a divine hound has been brought to heel by you.”

I couldn't help shaking my head. A thousand years later, our people had become ridiculously weak.

I stepped onto the surface.

“The ancestor has achieved sainthood through his physical body. He can withstand temperatures of 40 degrees above zero and 10 degrees below zero.”

As Su Hao learned more about the true reason humanity had regressed, he discovered that it was about more than mere regression. A much greater conspiracy seemed to be at work!