How to make the Shield Charm on the protective bracelet last longer had now become one of Albert's latest research topics.
Recently, Albert had flipped through quite a few books, and some methods could indeed make spells persist longer.
The simplest way was to concentrate fully when casting the spell, which essentially meant using stronger magical power to sustain it. The Duplication Curses were the best example: some duplicated objects could last permanently, while others disappeared on their own after a certain period, which was directly related to the person using the spell.
Chapter 58