This is tentative, people, but I think I hit a gold mine: The Revenants of Anarchy series has four books. And I've cinched the fourth book title.
Book 1 - THE CAIN LETTERS
Book 2 - CHIMERA FALLS
Book 3 - MALUMUNUS
Book 4 - B'RITHANAN: THE FINAL COVENANT
Currently working with the publisher on the title, seeing if it's a go. I still consider this a 'working' title, but so far it's the leading contender. We shall see soon!