@Zahnrad  
Thanks. I did word my request badly. I meant ‘story’ in the sense of what’s the plot, like how in Shadow of Mordor you eventually become a rival to Sauron.
 
It was late and I was tired. I can always go check this stuff out on TV Tropes or Wikipedia or whatever.
 
Thanks again.

@Ardashir  
“I mean the in-game story/reason for why the game happens?”
 
I’m not sure what you mean by this, but I’m assuming you mean why is Final Fantasy and Disney in the same universe? Correct me if I’m wrong.  
In-game, they are already a connected universe, Kingdom Hearts lore is known for being extremely complicated but using KH1 lore before it became a bigger puzzle, each Disney world is seperated from each other (for the most part), and you as the Final Fantasy OC Sora are able to travel between these worlds along with the help of Donald and Goofy who are ordered by King Mickey to follow the Keyblade wielder, which is you. It’s hard to say how many worlds are aware of the existance of other worlds but the one Mickey, Donald and Goofy are from seem to be aware.

Perhaps someone can enlighten me. What is the story behind the Kingdom Hearts game? I mean the in-game story/reason for why the game happens?

@Zahnrad  
Well, at least he can do commissions. ;)

Garble Should not be there. That space is susposed to be represented by friends or those closely linked the person whose “Awankening” belongs to. Honestly it make more sense to have Twilight or even Rarity. For they at least interact more positively with Ember. Still a great piece though.

Shame this guy doesn’t do requests.

Behold the Disney Princess of Kingdom Hearts!

Ember is best Princess.