User blog comment:FairyRaven/Fairy Tail Chapter 356: Tartarus arc - Prologue, Review and Commentary/@comment-82.20.156.238-20131020073039/@comment-82.20.156.238-20131020154914

There are so many possibilities. Like the reason Gray could control the Ice Devil Slaying Magic was because he's a half-human half-demon hybrid and it runs through his bloodline (or something) or Silver was Ur's husband and left before Ultear was born and that's the reason why she had immense magic power or you get the picture. But whatever it turns out to be it will definitely be interesting and this arc will be epic.