Humans had a strange trait.
They adapted.
They adapted too fast. To both good and bad things.
They'd take the great things they were having for granted.
Even though it helped them as a species, the trait was responsible for them neglecting many precious things.
For instance, peace and a white moon.
After 300 YAB, Dungeons appeared everywhere.
At first, humans panicked, but soon, they were using dungeons to their advantage.
Technology also skyrocketed during this period.
The levels of awakeners rose rapidly. Exploration of Ruins accelerated.
And…humans found out the ruins on the other planets.
After they passed a certain level in the ruins, the ruins gave off a blinding light and the entire planet it was based on shook.
Then before they knew it…the planets, no matter how hostile to life they were before, became habitable.
It was god-like and defied every common sense.