video; oops had to edit
That's right. I don't know if I can explain it properly... but a lot of modern technology in our world is powered orbal energy and the same, in quartz form, help us use orbal arts.
[ he thinks of a way to simplify this ]
ARCUS units are basically a new model of orbments. And orbments are devices we put quartz in. For example, if I wanted to use the healing art Teara, I'd have to equip a water quartz of the same in my orbment... And if I wanted to use any other arts, all I'd have to do is find the corresponding quartz and fit my orbment with it.
...Does that make sense?
[ He wonders if Machias or Emma, even Alisa could've explained it much better than him... ]