I've been thinking of how a lot of songs I hear relate to something I've read on this site. Here is a song that I think epitomizes Iylaine and Vash's relationship. I just imagine Iylaine singing this song (and in some cases Vash).

Here's a link:

http://www.youtube.com/watch?v=A_U6iSAn_fY

I cry every time I hear it. It's just so moving.

It even has a reference to their bonding!

Something always brings me back to you.
It never takes too long.
No matter what I say or do I'll still feel you here 'til the moment I'm gone.

You hold me without touch.
You keep me without chains.
I never wanted anything so much than to drown in your love and not feel your rain.

CHORUS
Set me free, leave me be. I don't want to fall another moment into your gravity.
Here I am and I stand so tall, just the way I'm supposed to be.
But you're on to me and all over me.

You loved me 'cause I'm fragile.
When I thought that I was strong.
But you touch me for a little while and all my fragile strength is gone.

CHORUS
Set me free, leave me be. I don't want to fall another moment into your gravity.
Here I am and I stand so tall, just the way I'm supposed to be.
But you're on to me and all over me.

I live here on my knees as I try to make you see that you're everything I think I need here on the ground.
But you're neither friend nor foe though I can't seem to let you go.
The one thing that I still know is that you're keeping me down