Dead and Alive by Dean Koontz

Dead and Alive is the third novel in the first trilogy of Dean Koontz's Frankenstein series. Originally intended to be co-authored by Ed Gorman and Dean Koontz, Dean Koontz stated that he would be writing this alone. by Dean Koontz.
Deucalion, the legendary monster, is a heroic figure dedicated to battling the evil that gave him life. The megalomaniacal Victor Helios has unleashed his engineered killers on modern-day New Orleans. Detectives Carson O'Connor and Michael Maddison are Deucalion's all-too-human partners trying to end the reign of terror of Helios's killers: Victor Frankenstein, having applied his own research to extending his own mortality, is now known to the world as Victor Helios. To the public, Helios is a philanthropic millionaire and a beneficiary to mankind.
In reality, he has experienced much in two hundred years since he created a man from fragments of the corpses of criminals. However, in secret, Helios has become obsessed with overthrowing true humans, which he refers to as "the Old Race," and replacing them with his superior creations.
After the failure of his first rebellious monster, he put himself through extensive bodily modifications to extend his life span and increase his physical power. This process has left his physical form scarred and deformed.
Unknown to all, he had created a clone of himself, who has the same goal as his original but considers himself to be as foolish as the humans he tries to replace... (Summary by Wikipedia)