Nice, now I want Project M even more...
That sounds pretty convincing, but I don't think Ganon and Ghirahim know eachother :P
Counter-arguments: There are many Skyward Sword items, so who knows, there might be a Skyward Sword- only character as well.
That's about all I can think of... But I want a non-Fire Emblem sword character D: Give Ganon his sword and I'll be satisfied.