I actually don't have much of an idea since i've not seen Death and Rebirth (or even the series ending as i've complained on this board before
) but could it be 'Tamashii no refrain' (Soul Refrain)? I remember listening to it once and reading that it was a Death and Rebirth theme song, although whether it's the *opening* theme, i dunno ^^;;
And y am i replying when i'm not sure of the answer? Who knows, i just felt like saying something ^_-
"This is my story. It'll go the way I want, or I'll end it here"
--Final Fantasy X