[@Cio]

	Okay, I have many things to say:

Firstly, her background of [u]Pre[/u]-Sin-hood is supposed to be how did she get the title of the Sin of Greed. Not her entire existence up till now.

Secondly, demons are seen as evil and sinful, so if she was the greediest, and they hated her for it, how could she gain the title? (apart from those who also wanted the title)

Lastly, the sin ability is an ability on the demon of that sin has. Say, the sin of wrath. His ability could be to make everyone in near proximity angry as all hell, causing them to go into a frenzy, or lust having the ability to seduce anyone they want without effort.

	It's a good start, but put more thought into it please.

EDIT: Also, for her real age she's Twenty? because that's what two X's mean in Roman numerals.
And if your trying to say 200, that's kinda young in demonic terms, and that would be CC in roman numerals.
if not going for roman numerials, use actual zeros so it actually looks that way.