A character that is already dead in Game of Thrones looks set to make a comeback on Game of Thrones Season 6. Though, it is likely that this character will feature in a flashback/dream sequence rather than coming back to life.
** Spoiler Alert **
Tyrion’s traitorous lover, Shae, played by Sibel Kekelli was spotted on the set in Peñíscola, Spain last year along with with GOT creator David Benioff and Conleth Hill (Varys). Peter Dinklage is also reportedly filming on the same set which could possibly mean a flashback/dream sequence featuring Shae and Tyrion. Sibel is also reportedly staying at the same hotel as rest of the cast. You can check the images below.