The Kildren and An Enemy That Always Wins

Image by [puamelia] via Flickr

The Kildren are products of a genetic experiment. They are the main characters in the movie The Sky Crawlers. The Kildren never grow old. They live until they are killed in battle.
I just had to write about this. Because i'm watching it right now, and because the movie mentions something about an enemy that must always win. The Teacher.
The Teacher always kills the Kildren.
In some way, I think that this "Teacher" is Entropy itself.
The Second Law of Thermodynamics is built into this universe. Things break down. Our bodies break down. Life ends.
Perhaps the Methuselarity is something to set hope upon. But then again, it might just be like the hope of eternal life that religion dangles at our face.
Why does everyone want to live forever? Is there truly an enemy that must always win?