The backstory of Vanitas from the novels.
My friend Ikkin (or KitsuneIkkin) posted this on KHI and I thought some of you might find it interesting
http://www.fanfiction.net/s/7075624/1/DARK_MEMORY_The_Truth_of_Vanitas_Behind_the_G-%20ame
The novels aren't fully canon, of course, but it's still pretty good fodder for RPing and personal-canon if you don't mind a more sympathetic portrayal of Vanitas. (He's still not anywhere near nice,fortunately, but it's hard not to feel bad for a being who's in constant pain, tormented to the point of homicidal fury by the existence of the Unversed but left in physical agony when he destroys them)
http://www.fanfiction.net/s/7075624/1/DARK_MEMORY_The_Truth_of_Vanitas_Behind_the_G-%20ame
The novels aren't fully canon, of course, but it's still pretty good fodder for RPing and personal-canon if you don't mind a more sympathetic portrayal of Vanitas. (He's still not anywhere near nice,fortunately, but it's hard not to feel bad for a being who's in constant pain, tormented to the point of homicidal fury by the existence of the Unversed but left in physical agony when he destroys them)