[No doubt Ignis' disgust of the concept is clear simply by his tone when he speaks the word. It isn't his knowledge of the practice that drives that distaste, as much as the way it has been used against his country and his king for as long as he can remember.]

Centuries ago, magiteknology was used by a now lost, but formerly powerful and advanced civilisation. Through research into that, and in the pursuit of recreating the 'glory' of Solheim, the Empire discovered a way to weaponise the daemons that plague Eos thanks to the scourge infecting our planet.

[There is a tightness in his voice as he goes on, as much as he tries to keep it objective for the sake of Carlisle's curiosity.] They use them in their armies. It took only two years for their most powerful developments in infantry to overcome Lucis entirely.