The Gunther Tales.
The first Gunther book, "My Gun is My Passport," is an international epic. It's...epic. It is possible I will never be able to write such an epic tale again. It is exhausting and time consuming. (But I do have a Gunther-goes-to-China story on the back burner which is an international, multi-character, epic adventure, much like "Passport".) I consider "Passport" to be like a big, pilot episode if you will. You meet Gunther and Jefe, etc. The book won an award in Hollywood.
The second Gunther book "Last of the Gunmen," and the third in progress right now "Rio Grande Black Magic" are like...episodes after the pilot. We know who Gunther is. We know who Jefe is. I don't have to slog through all the character building of a first or solo book. A short or clever synopsis-piece can handle a catch-up overview. This series progression is a writing method true of so many, if not all novel serials, TV shows and movies. Writing 101.
In my mind, Gunther looks like the actor Rutger Hauer, who to me, never got a great serial, "hero" part in movies. I always INSIST that our artist use Hauer as a model for Johann Gunther on the front and back covers.