User blog comment:PUNCHURPREGNANT/Gray and Silver Predictions/@comment-5570219-20140531045241

1) Natsu in the earlier chapters of tartars said that silver has the smell of gray 2) When Silver was in battle or something, someon mentioned gray and he asked him to " not mention this name to him.

So far in the story, Gray and Silver haven't meet yet. An silver's involvement in the plot was not much. I predict that they will have a battle in the end where Natsu will battle E.N.D. And as the battle go on, everything will be revealed in Silver's perspective.

There are 2 possibilities ( I think) 1) Silver is Gray's father that he actually survived the Deliora attack. 2) (referenced from one of the comments.) Juvia and Silver are Gray's parents? What? Time travel thing? emm... this one i think is less possible. 3) Time traveled son of Gray. (but i think that if so, he would less possibly fight them.

Overall, silver is the most possible to be Gray's father. :p