I have a lot of guesses but I'm gonna go with Cait Sith mark one.
Like i coward I hide inside
never to be seen (Reeve)
and like a dog I obey anyone
Anyone who might know me (remote control)
The ball I toy with I hand to my master (this could be literal I forget if Cait has a ball)
As my memories scream and try
But its no use for I'm almost gone now (The seen before he sacrifices himself)
and so is somones life (Aeris dies shortly after)
