Are Prompto, Gladio and Ignis dead since they joined Noctis in the afterlife to defeat Ardyn? I made a litte post about that over on Neogaf where they are still debating.
For everyone who is still like:
But the bros are all dead because they were there in the afterlife to help Noctis defeat Ardyn! D:
The final defeat of Ardyn does not take place in the afterlife but in the heart of the crystal.
After Noctis gets sucked into the crystal this is what Bahamut explained to him:
"The heart of the crystal, wherein lies the soul of the star.
And it is in this place, where the king will gain the power to fulfill his calling. By the light of the crystal and the glaives of rulers' past."
If that wasn't clear enough, the Ardyn defeat takes place in the exact swirl of blue and violett with crystal particles floating around in which Noctis was when he met Bahamut...
It's not only not the afterlife but the bros are also not there in reality when Ardyn is defeated. They are a mere vision of Ardyn. We only see them for a second from Ardyn's point of view. He then shakes his head in agony and they are gone again. It is only Noctis and the former Lucian kings who defeat Ardyn, just as Bahamut foretold. (I think Luna and Regis too were only visions by Ardyn.)
The only afterlife scene in the game (the campfire scene took place before entering Insomnia to confront Ardyn) was the scene of Noctis' and Luna's wedding. Regis was with them (in voice) but none of the bros attended. You would think they were invited if they were dead as well, right? That was also the point of having the bros there in a picture...unless you chose Cindy.
