Monster hunter nemesis
(Book)

"Agent Franks of the US Monster Control Bureau is a man of many parts--parts from other people. Franks is 6' 5", all muscle, nearly indestructible, animated by a powerful alchemical substance and inhabited by a super-intelligent spirit more ancient than humanity itself. Good thing he's on our side. More or less. Sworn to serve the US from all monsters, Franks has only one condition to the agreement. No matter what, the government is never, ever allowed to try and make more like him. Should they try, the agreement is null and void. Project Nemesis, headed by the director of the very agency Franks works for, is making more like him. And he isn't making one, he's making thirteen. Now all bets are off and Hell hath no fury like a monster betrayed"--,Provided by publisher.