User blog comment:NoNickNeeded/Urano Metria power source?/@comment-8153438-20130901224733

Maybe Urano Metria is a combination of 3 magics... Lucy's Stellar Spirit Magic, Jellal's Heavenly Body Magic and Hibiki's Archive... Lucy was able to learn it thanks to Hibiki's info.. The stars are heavenly bodies too that sometimes it makes me think if Lucy and Jellal are related in some way..

About Urano Metria's source, Hibiki is the source and he probably intended to teach it to Karen Lilica. But to cast it, Lucy need the help of the Celestial Spirit Realm too and the Ethernano of Earthland.. So all three is my answer.. :)