User blog comment:KnocknickKnock/Celestial combination attacks with Lucy"s 10 zodiac keys./@comment-3424593-20140310043620/@comment-7418318-20140310092808

The "sealed" theories in all their different varieties would also explain how Lucy could grow so powerful in such a short time.

I mean just look at her. She's been a mage for something around one year and has already surpassed others who've been mages for more than ten years. And all that even though she's not particularly dilligent in going on missions (which she does just as much as is necessary to earn a living) and training (which we only ever saw her doing prior to the GMG) to the point that some might call her a slacker. And still she's growing at this phenomenal pace.

If she's sealed and said seal is either weakening over time, or slowly being broken for some other reason, it would neatly explain how such a rapid growth is possible.

But if this theory turns out true, I hope that she was able to learn the One Magic as a child, rather than being infused or somesuch. Just being given this power without having to earn it, would make it seem as if she couldn't do anything of her own and had to rely on help from others.