User blog comment:FairyRaven/Fairy Tail Chapter 470: Hybrid Theory, Review and Commentary/@comment-1359322-20160125125836/@comment-9595671-20160126184802

Yeah, he may have hidden it too. If we learn why Serena switched sides then we might know for sure if it's magic he recently got or not. It does seem more likely he could have hidden it because I don't think we learned when Serena changed sides.

Learning how to effectively use 8 Dragon Slayer magics in a year when you never had a dragon teacher doesn't seem physically possible, just one or two at best.