It is inevitable that a good guy will end up with the rinnegan whether it be sasuke, naruto, or Obito. In the end everyone who died will be revived. Agree?
Gai is good as dead. The moment he opened 8th Gate he signed his death warrant.
This is just a flashy and dramatic way of going out, so that way, ppl can say, "Gai died from his own jutsu, not from Madara."
Gai is one of my favorite characters but I think it would be good for his story and the manga's story for him to sacrifice himself. He is showing the power of youth even at the expense of his life, to save his comrades. His theme is that shinobi should always put their maximum effort to carry on this eternal youth and to use it to protect the future youth.
I don't really see Lee losing his closest rival and his teacher in the same way either, but it seems what Kishi is going towards. Also, it'd seem a little weird if Sasuke saved Guy.
I'm on the fence with his survival. I'm leaning toward his death, since his flashback chapter and speech to Lee, but you never know. If he is saved, my money is on Obito doing it.