Is 'The Gray Man' based on a book? Yes, "The Gray Man" is based on a series of novels by Mark Greaney. The books follow Six, a.k.a. Court Gentry, a freelance assassin and former CIA mercenary.

However, I think part of the reason that D.Gray-man, as a series, stood out to so many people is that it used death as an overarching aesthetic and theme. The very concept around the D.Gray-man's ...