User blog comment:LastationLover5000/Fairy Tail 285 - In Which "Glitter" is redeemed after Twilight embarrassed the word (MPF)/@comment-5016119-20120603045756/@comment-5441712-20120603182448

The only way what Cana did could be "cheating" is if she beat someone up and stole the spell. Mavis, a former leader of her guild, gave her the spell, and probably felt that she deserved it.