Earth, 2102 C.E (beginning of 22nd century)
Technology was booming and space travel was possible with some humans even settling on Mars. In search of a planet with a similar atmosphere and ecosystem to our Earth, we tried to search every planet in our system, but we did not find any human habitable planets. We could not find anything resembling our earth.
The search was going on when we reached where twelve different planets were orbiting around a single planet, yes not a sun but a planet, it was around 2115 C.E. Later through research we found out it was a solar system similar to us with living being but for some reason, everyone had died out. All the twelve planets were black, not a spec of light. We found many satellites which were now not working.
We were able to retrieve some information from those satellites, which lead to a shocking truth. All these planets had died due to some creature. Even this system's sun was eaten by this creature. That creature was the planet all these dead planets were orbiting around. Now that creature was sleeping or dormant.
When the various countries found out a creature was living just some light years away which could destroy a solar system which was three times larger than ours, they station a 2 million strong army in that solar system. If that creature woke from its dormant sleep, the 2 million-strong army could intercept it. But the fear of waking that creature did not stop some big nations from experimenting, they were able to collect a very small amount of that monster's blood and faeces. We were not able to identify most of this creature's composition, it was a carbon-based living being but also different.
A single energy stood out as it was present in every single sample from the creature's blood, faeces and even the dead planets. But for some reason, it was not present in our solar system. After some experiments, we were able to infuse that into gunpowder, which created a weapon of mass destruction which was stronger than a TNT or RDX similar to a nuclear explosion and it was not even reactive material like uranium but gunpowder. Later it was infused with a hydrogen bomb which created a weapon with mass destruction more powerful than nuclear weapons and the hydrogen boom is known to mankind. In a weapons test, it annihilated one of Saturn's moons without anything remaining, no derby or small asteroids. Seeing the result many nations got greedy for such power, just like when a nuclear bomb was made.
They sent some of their premier scientists to collect a large sample which lead to the waking of that monster. The creature opened its huge mouth and swallowed the whole dead solar system within minutes like some black hole. The whole area where the solar system existed with many moons, asteroids etc., nothing was left, only one thing, a huge octopus-like creature. Later the creature started to move towards our solar system. Within a month, it reached Earth. It destroyed everything in its path. But due to some unknown reason, the size of that thing kept on decreasing after it devoured the dead solar system. It was half its original size when it reached Earth. It kept decreasing.
It eventually landed in Peru and started its rampage which lead to the destruction of half of South America. But the thing stopped itself in the state of Para, Brazil. Finally, we were able to kill it with weapon X, a weapon created through its blood.
South America was in chaos. All the major religious sites and famous structures like Pyramid, Sacsayhuaman, Nasca Lines, Stonehenge, and Kailasa temple were destroyed within weeks after this incident, then plants and animals started to mutate and lastly even the continents started to move, earthquakes, floods and volcano was commonplace. Most of the humans migrated to the spaceship.
Within two years seven continents were nowhere to be seen and only two huge continents were there. Even a lot of sunken cities like Atlantic, Dwarka etc. started to rise above the sea floor.
The human population which remained on Earth was about 100 million while in outer space was around 850 million.
The world stabilized for 10 years, earthquakes decreased and volcanic eruptions also decreased. Even the people who were trying to live in spaceships came back as there was no fuel or energy for the spaceship to remain operational.
Now only two huge continents remained Gondwana and Laurasia. Many new species were born in those 20 years, a lot of them also mutated and became very strong. Guns did nothing to them, but such monsters were very rare. But not just animals evolved, even humans evolved and gained special traits like controlling the elements, strength to lift a spacecraft as if carrying a cycle, etc. They protected the people, their community, and newly built cities and towns, but just when everyone was getting accustomed to this life, dimensional gates started to appear all over the world.
Later, around 2158, the now world government was created. Since then 990 years have gone by, and our population has stabilized to 3.2 billion but we only occupy only around 20 per cent of the habitable earth. There are currently 800 or so cities ranging from small-scale, mid-scale and large-scale cities all over the seven provinces controlled by the government. All remaining are forest, desert, lake, river etc. It is inhabited by various monster and beast-like goblin, dragon, orc, orge, merman etc. but the most dangerous is the sea and oceans which remains unexplored and many high-ranked beasts exist.