Though the use of Soul Crystals seems like it is possible for anyone with base level skill. It seems like our characters ease and swiftness to control the various powers of the crystals seems to be what separates them from most others. It is nearly commented in every job quest on how quickly it seems like our character seems to be able to take on any fighting style that is presented especially considering some of those powers like Warrior's Inner Beast or Dragoon's connection to Nidhogg’ s power would generally be too much for most people to handle on their own at the same time. Given nearly every combat form we have is mastery over A ether in various forms, it probably makes sense giving the background they seem to be pointing about our Warrior of Light.

However, I'd probably also say this flexibility does come with a few weaknesses, given that many of the Scions display abilities that do not exist in our job archetype such as Alphinaud’ s different carbuncles or Y’shtola unique spells she utilizes. We seem to be limited to the memory of the crystals or in the Case of Machinist or Blue Mage where we are literally shown what to do specifically, we're heavily dependent on the crystals to define the abilities our characters use. Though much of that may simply be gameplay convenience.