Harry of the Vale Challenge
Harry is born to Jon Arryn and his second wife Rowena or a different wife before Robert's Rebillion
-Harry could be frosted to one of the other great houses.
-He could has a falling out with Jon over how Robert's Rebellion ended with the death of Elia Martell and her children by Tywin Lannister.
I would like to see him fostered in Highgarden, Sunspear or Riverrun