User blog comment:Miskos3/Fairy Tail Chapter 483: Seven Stars, Review/@comment-109.176.129.254-20160428165201/@comment-25111584-20160430183729

God Serena is the strongest Dragon Slayer besides Acnologia. His dream seems to be to slay Acnologia. It makes perfect sense that he'd defect to Alvarez, whose power has been collected for the sole purpose of countering Acnologia. And GS' plan worked perfectly... up until the moment he came face-to-face with Acno and was gutted, of course, but you can blame that on the uselessness of Zeref's (or Invel's) strategy. :P

Maybe it's his extraordinary irrelevance to plot despite the immense hype that disappoints? Doesn't really matter to me, but I guess it's just a difference in perspective. /o/