User blog comment:IamJakuhoRaikoben/Chapter 420: Lamia Scale's Thanksgiving, Review./@comment-7418318-20150216144642/@comment-76.124.155.27-20150216152454

he/she still brings up a really good point, that Lucy has to be battle harden to have that much confidence to openly challenge Natsu. My best guess is she remembered the feeling up temporarily becoming Aquarius and figured out how to merge with her other spirits.