Surviving In Alien Earth

A man who was convicted for deathrow is later taken to be experimented on. After two hundred years of been lab rat and been put to cryogenisis later, he is shipped to a hostile Earthlike planet where he is supposed to annahilate every organism that is to be a threat towards humans. With an ever evolving body and a moral sense so low he might as well be said not to have it, did humans make a mistake to send him here?