Where it started. The game's title ties into the concept of magic energy being interwoven on ley-lines that have gotten out of alignment, thus tying the mechanics of the game to the story. Your main character will be one who can interact with these lines. The other characters are varying types of magic users whose static magic skills benefit from the alignment of the area and can use special skills dependent on what the current affinity is. Your main character however, cannot use static spells, only use whatever elements are currently strongest.
The grid. Under the hood this will be handled by having the current affinity tracked by basically and x, y coordinate that has a max and min value of whole numbers. You can see from the shading how elements will be calculated and where rare abilities will unlock (the areas with hatching lines). The x axis will be between Wind and Earth and the y axis will be between Entropy and Order.
How it might visualize on the battle screen. The eight major arcana points will illuminate according to where the current affinity point is, with those closest being brightest/most saturated and those further away being duller.
And the first rough draft of the gauge, completely slapdash in photoshop, will be properly pixeled or digi-painted later.