Just making a quick theory.
In the flashbacks with Kaguya's sons taking on the Juubi, it appeared that Hamura's stance resembled the dead reaper seal (i'm forgetting the exact name at the moment). With that plus the hint of Kaguya even mentioning her sons, I believe this is the only thing that she fears. Personally, I believe that Hamura invented the seal and turned in to the reaper himself (some other thread goes in to more detail on this). But why I am convinced that this is the only way to beat Kaguya is because it is the perfect tool to be a true hero, by self sacrifice.
I think that Kaguya will be too strong to be pulled in by Naruto or Sasuke alone, I believe that they will both have to perform the seal simultaneously to get her. (The fox was too much for Minato and Orochimaru was able to fight against the 3rd, so I think that Kaguya will fight like crazy.)
However, Naruto and Sasuke won't die. The seal traps your soul/spirit into his void/dimension. Because Naruto and Sasuke have Ashura and Indra's spirits within them, I think that it will be Ashura and Indra's spirit that gets sealed and not Naruto and Sasuke. I know this doesn't really go along with the traditional idea behind reincarnation, separate spirits and all, but this is a manga and they didn't awaken their spirits till just recently and it would seem there were two Indra's with Sasuke and Madara being alive at the same time. This will break the cycle of fighting between Ashura and Indra truly bringing peace to the world.
In the flashbacks with Kaguya's sons taking on the Juubi, it appeared that Hamura's stance resembled the dead reaper seal (i'm forgetting the exact name at the moment). With that plus the hint of Kaguya even mentioning her sons, I believe this is the only thing that she fears. Personally, I believe that Hamura invented the seal and turned in to the reaper himself (some other thread goes in to more detail on this). But why I am convinced that this is the only way to beat Kaguya is because it is the perfect tool to be a true hero, by self sacrifice.
I think that Kaguya will be too strong to be pulled in by Naruto or Sasuke alone, I believe that they will both have to perform the seal simultaneously to get her. (The fox was too much for Minato and Orochimaru was able to fight against the 3rd, so I think that Kaguya will fight like crazy.)
However, Naruto and Sasuke won't die. The seal traps your soul/spirit into his void/dimension. Because Naruto and Sasuke have Ashura and Indra's spirits within them, I think that it will be Ashura and Indra's spirit that gets sealed and not Naruto and Sasuke. I know this doesn't really go along with the traditional idea behind reincarnation, separate spirits and all, but this is a manga and they didn't awaken their spirits till just recently and it would seem there were two Indra's with Sasuke and Madara being alive at the same time. This will break the cycle of fighting between Ashura and Indra truly bringing peace to the world.
