Severance

The next morning, the gang heads to the north star's sacred place, which is called the "Nine Purple Fire" because of its purple hue. There's a seal on the sacred book, but it's hard to crack because the seal is on its own. The story goes something like this: The north star was overrun by demons thousands of years ago, and it rained down the Nine Purple Fire for seven days, seven nights, and then put it out of action so that it wouldn't cause any more trouble. Since then, nobody has ever been able to enter the sacred place.