Spare parts, or to be a test body for experimental drugs and procedures. The person he is a copy of was a concert pianist and their mother was doing whatever she could to preserve his career. It was a dream job she wanted to have for herself, but couldn't obtain due to an accident that took away her ability to play.

But That Man grew bored and walked away from it all. My friend was deemed useless. As he grew to remind her more and more of her lost dream, she tolerated his existence less. He went to live with That Man instead, only to be manipulated by him as well.

I was hired as part of that plot.