The three Kingdoms of crystal

Luna Lyall is the head of the royal guards in Nethilor, and fights alongside her half-sister Alma, to keep the dark creatures away from the kingdom. However, when they see that they will not be able to do this forever, and the harvests of the village decrease, they decide to bring back the magic that the land had lost. However, the guardians of magic do not seem too enthusiastic and refuse, but offer to teach them magic.
However, seeing potential in them, those who took the magic from the country study them carefully.
will magic be worth the risk of life and the pain?