Quote Originally Posted by Aurons Ghost
Yes it is...
However, you clearly can, as Advent Children showed us:]

That says to me that Square intended their little ways of doing these upgrades/abilities to be realistic in the manner of the game.

There is no Sin in the real world, but in the game, it is a very real mechanic, just like I think that the spheregrid would be:]

(they also don't show them holding their weapons outside of battle. Perhaps they place the spheregrid wherever they hide their armor and weapons)