Considering IRL, the modern military has hardened its tech to be resistant to EMPs, I always find it amusing to see the fictional plot device treated as the Be-All-End-All for disabling mechanical devices :3
Hey, Eos was always immune to EMP. You can search her CSs around the guild and see. It's not like she would be dumb enough to build machines with such an obvious weak point. That's what I'm finding more fun here.
Magical machine disabling attacks are another whole ball game, though, since they aren't technically just EMPs, but very much probably mixed with some demonic energies to make it work against Machina.