The Resonant are Imperial supersoldiers in Final Fantasy XIV. They are imbued with a powerful artificial version of the Echo, granting them the ability to detect minor changes in the local aether, in turn allowing them to effortlessly predict and avoid incoming attacks. They can also manipulate the power of the aether.
Though the Garleans are intellectually and physiologically superior in almost all aspects, they lack the hereditary traits required for the manipulation of aether, thus making it impossible for them to use magicks. With this weakpoint, the Garleans sufferred to decades of oppression by other races, and were eventually driven to seek shelter in the cold northern region of Ilsabard. Fortunately, said region was replete with vast deposits of ceruleum, which led them into the development of magitek: a revolutionary technology conceived to compensate for their disadvantage.
It was with magitek that Garlemald grew strong and became an empire, however, Aulus mal Asina believed that it was just a temporary solution to an intrinsic problem. What he really wanted was not to rely on devices instead of using magicks. Through modification of the Garlean genome, he argued that it might be possible to enhance a subject's ability to manipulate aether, effectively empowering them to wield magicks. Alas, his theories were met with consternation in the imperial court. Only Zenos yae Galvus, with commendable foresight and wisdom, deigned to support his research.