Yup, thought of this too!
You see, the visor can sense the build-up of magic and is able to redirect it to the power supply of the “HG” (Hypno Gear) and use it to supercharge it, leaving the user stuck on using his or her magic on the device till it’s reached an amount that it no longer needs the charge. I’ve put a limiter on the HG so it won’t keep draining the magic to a dangerously low level. In other words: the harder you try the stronger it gets~