아르스 마그나

Ars Magna (大いなる秘法(アルス＝マグナ)) is the most secretive technique among the Crossbellan alchemists, ultimately used by Mariabell Crois to express the power of a reality changing power that even surpasses the capabilities of Aidios as part of the Azure-Zero Project. She later compares the concept of Ars Magna to the existence of the Grandmaster.