oh, he did a mercy killing on Duke because he's body was beyond fucked up, he didn't want ...

oh, he did a mercy killing on Duke because he's body was beyond fucked up, he didn't want him to suffer because of the side effect of the drug, good guy, also grandma was right, if Duke knew that the side effects would be so severe that it would immobilize him for the rest of his life after its usage, he wouldn't take the drug