The Day the Universe Contracts

One day, the universe will expand to its limit, then begin to contract.

The protagonist transmigrates a hundred years into the future, only to discover that his home has become a tourist attraction.

I can upgrade anything!

"It's him! That man has returned!"

"The man from behind the walls, the guardian deity of the Dragon Kingdom! He's back!"

The greatest scientist of the past uses all kinds of bizarre weapons he DIYs in the apocalypse, building a city and setting up tower defenses! He'll construct the ultimate apocalyptic home, upgrade tower-defense weapons, and upgrade vehicles!

This novel and its characters are entirely fictional. Any resemblance is purely coincidental. Do not imitate.