In the Black Dragon World, there were two ways to register an account on one's magical power top-up device.
One of them was to successfully practice the ❮Meditation Technique❯ to the first level before going to a temple to register an account, and receive one's own magical power top-up device.
The second way was for an inhabitant of the Black Dragon World to wait until they reached the age of 14, which was considered to be adult age in the Black Dragon World. Then, at the coming-of-age ceremony, civilian-type magical power top-up devices would be issued to these people in batches.
In the Black Dragon World, this device was a convenient thing. Nearly everything one needed in their daily life could be provided by it. The 'magical power flow' could be used as currency. For example, when going out to eat or shop, one could use it to pay for things.
❄️❄️❄️