He's not really a doll, or a puppet, because he is indeed alive, but he does have genetics that were "stitched" together just like how half his body needs prosthetics to move/function properly. He's a semi-corrupt politician after being dragged from one country's military to the other because he's somehow pretty good with words.

He was a conjoined twin, but was separated from his twin sister, his sister regenerated limbs fine, she was the "perfect" specimen, he did not so half his body is a lil' screwed up.

When the other military found him they thought he'd die since he had a hook through his chest and was shot in the head dead-blank, but he didn't. So they were like "hey, he was good for the other side, let's let him join our military, by force!" Which is kind of dumb but homeboy here didn't really like the country he was 'originally' from so he went without much issues.