How the magic system works relates to the inciting incident of the whole premise though. It's a core concept from chapter 1 and the basis of all the major events, factions, and the driving mysteries of the story. Dumb. Imagine if you said this about FMA.
(It's also pretty good as magic systems go, although as a result it has the silliest looking magic circles of any manga by a wide margin, since it's the only one that tells you what the glyphs and their positions mean and stuff instead of simply trying to draw them as cool as possible.)
Anyway to answer the question it's a pretty good series but don't expect things to move in a hurry, it's slow burn for a long time before shit begins hitting the fan.
I think it's been a couple years for me too, I should pick it up again. Thanks for reminding me.