I’m sure some people have noticed that:The most of these numbers come from religions, like 7 33 153. I categorize them by rarity. The harder it is to get, the smaller the number, and vice versa. Simply put, the number reflects the rarity of the item.
As for the sleeper and other ancient civilizations, it was because the Sansha series was almost complete. I just wanted to do something more, so I started researching the history of Sansha, trying to find something I missed. And I found that in the plot of the game, Sansha was collecting these ancient technologies, researching and applying them. So I decided to add them to my collection.