Glistens Series by Chess Desalls

A guardian can't shine without the song of her ward.Marian Spritz won’t gain guardian fairy status if she fails her summer school project. But when she hears a call for help—a song felt only by Glistens—she must choose between not letting her schoolwork and teammates suffer and protecting a ward who faces grave danger.

A guardian can’t hunt without chasing rabbits.Marian’s first assignment as a commissioned Glisten is bigger than she ever dreamed. Demon shadows known as rabbits have been attacking the weakest Glistens and causing them to disappear. Marian wants answers. But her only lead is through a network of underground tunnels, not navigable by the Glistens’ human forms. Will she succeed at finding the missing Glistens, or will her attempts fizzle and burn out?