I remember when I was a little too young to have a job. I played the demo of this game now and then, trying to figure out what it's all about, how to 'level up' in it, where to go... this game is truly unique and separates itself from any strategy RPG I have ever played. Square Enix hit on something really good with this game, and that is the idea of strategic army-like combat. You get party members of all kinds, from simple soldiers to guild mercenaries with special traits/powers and the generals of Athlum, who are undoubtedly some of the most powerful characters I have. These characters are organized in to "unions" which are groups of units on the battlefield. Improving your characters is done through what actions are taken the most by them, so if you have a character using mystic invocations a lot, he/she will improve in his/her mystic invocations (though you can certainly have them learn more than that, depending on the character). There's no real "leveling system", Battle Rank is more of a bounty-like rating based on how well you've done in battles (except that it doesn't decrease), and will affect how tough your enemies will be from there on out. It's mostly about having your characters use what you want them to get better at, and then utilizing those growing skills on the battlefield appropriately, which I really like to grow them!
Here's the catch that separates this from your typical Strategy RPG: They don't act singly. As I mentioned with the union system, they actually act as a group, so you select from 5-6(?) battle commands which vary based on many circumstances (you can see the wiki page for this game for more on that if you're curious, I highly recommend reading up on it before buying to make sure this game is something you'd want! Even try the demo!) You might get a command that says "Attack using Combat Arts" and "Attack using Mystic Arts". Selecting the first would have all units who possess a usable Combat Art use it, unless the AP cost is too high in which case they'll do a normal attack. The second would have all units who know a mystic art (not all units can be mystic users! Your main character, Rush, however, can learn all mystic arts throughout the story... I won't spoil how, that's what the wiki is for) use the one they know that doesn't go over the AP budget for that turn; Those without mystic arts would do a normal attack. Many factors influence what option shows up the most, or with the results you want, and it's these factors on the battlefield and in the character's training that make strategy all the more important. Organizing your unions appropriately, with formations that match the role you have in mind for them, and proper battlefield wit when the tide starts turning, make this game quite insane.
I highly recommend this game to anyone who is looking for something more... unique in the genre of Strategy RPG. First of all, I recommend reading the wiki, watching some Youtube videos, and playing the demo before you buy. This game isn't for the faint of heart, but it also isn't overly punishing (unless you just try to zerg everything without any forethought at all to your foe's strengths and your own weaknesses) I can safely say, that this is the most unique Strategy RPG I have played to date, on Steam and off Steam.