Was thinking of this idea what if SE/FFXIV introduced (2)new crystals Light & Dark.
Light could be gained randomly and/or through use of craft ability at final synthesis point.
Dark could be gained by Desynthesis, randomly.

Both these new crafting crystals could be used in new ways to craft items. Im thinking either adding slots? Or, making crafting easier? or maybe a shimmer to gear(need all five part and/or craft "shimmer" glamour plates light/dark?