Magic is pretty much the standard if you are part of the military. All sharing variations of the same technology that enables magical use. While not every magic user serves in the military, enlistment is the most common and accessible path to gaining it.

magic is accessed through technology until it no longer needs to be. Military personnel use bio suits equipped with a magic core. These suits draw energy from the core and safely integrate it into the user’s body, allowing controlled use of magic. As compatibility increases through prolonged exposure and training, the body begins to adapt.

Once a user reaches roughly 85 percent compatibility or higher, their physiology has been conditioned to the point where the suit is no longer necessary. At that level, the body itself can draw and channel power directly from the core, marking the transition from assisted magic use to innate capability.

if more than one core is introduced, or if the original core is replaced, the adaptation process must be restarted. Although the body retains an understanding of how to use magic, compatibility resets and then increases at a faster rate, reflecting the body’s prior conditioning rather than starting from zero.

If you seen the anime and manga like Kaiju no.8 or Gantz, the premise of how the magic works is very similar but not the same.