Yeah, that's true... We didn't really have enough time to figure out where you would end up going. [Except of course, Naoya knew already and didn't bother to tell anyone until just moments before Kouki had to leave. Sigh.]

What if you decided to become the Messiah though? Would you have lived in heaven, or would you have just stayed there for a certain period of time like in the demon world?

[Assuming and hoping that Kouki lived through and won the war, he would end up coming back home. But would he just live in heaven and not come back otherwise..?]