Mutual Erosion

In 2032, a mysterious world fell from the sky and gradually merged with the human world. The disaster began... At first, people thought it was just a coincidence, or an accident, and the sun rose as usual the next day. But this time humans were disappointed, because the sun never rose again the next day. Not just humans, the whole world is starting to go crazy. Some things disappear, but other things appear. Is it all over? No, it just started a new era. A new era without the sun...