The very first dimension appeared after engulfing a large human city. At that time, no one knew what a dimension was or where those humans vanished.
Because just like the slum district, the entire city was engulfed under a white fog, and no one could get inside.
It was sometime later that people found out that this process was known as 'dimension formation.'
When a new dimension was descended on this world, based on its rank, it would take a certain amount of time to form fully, and then a 'dimension gate' would appear on any random spot, which was the sole entrance and exit inside a dimension.
There were seven ranks of dimension humans had denoted to this day by the time they were taken to form.
Iron rank, which takes around five to ten days to fully formed a dimension gate.
Bronze rank takes 11 to 30 days.
Silver rank takes 30 to 40 days.
Golden rank takes 40 to 100 days.
Platinum rank takes 100 to 200 days.
Dark Platinum rank takes one year to two years.
