User blog comment:WhiteArmor/7/@comment-7/@comment-777/@comment-453884-20100514221155

Layla Heartfilia died on that same day and Lucy seems to have the unique ability of summoning more then one of her celestial spirits.

I also have an idea of a question Lucy asked: Why would a dragon teach someone how to kill it? I think it isn't for killing dragons even if they are called dragon slayer. I think they are trained so they can battle alongside their dragon against other dragons and slayers to see who would become the next Dragon King...