I really don't want Shinya to die. 😭😭😭

wait is he going to???

I don't know, but if I understood correctly he and his team were revived by Guren (which destroyed humanity), but they just continue to stay alive for 10 years or so and then die. And if they would ever find out that they theoretically died already they would die right away.
Because of this Guren tries to find a way to save them.