Thread:Unatratnag/@comment-24166297-20150714044311/@comment-25737724-20150714140735

Not dying is immortality.

I'd view self-sustenance as not needing food or air. Just because you don't die without it, doesn't mean you don't need it or use if for energy. In the same way in some lore a vampire needs blood to function - they're immortal but they become just an empty shell if they don't get the blood they need for sustenance. You can pour blood on their rotting bodies and then they come back to life. I don't know if it's ever been stated that The Immortal always functions without food or air. If you can get that reference, we can put it, otherwise it's speculation.