From the update:
Thanks to a previous working relationship with Paradox Entertainment, we have been able to secure a limited license to add some great Robert E. Howard characters to a custom tile pack for The Duke. Conan and Solomon Kane will soon be joined by two others in this limited edition set, the extra characters to be named in the next day or two as we finish the selection and design process.
Like the Three Musketeers, this tile pack is available as an upgrade to any physical copy of the game being received as a reward. It will cost $12, which includes any extra shipping charge. Simply go to "Manage my pledge" and increase your pledge accordingly. We will be able to see it. But to be certain, when you get your emailed survey at the end of the campaign, post a reminder as to which upgrades and rewards you expect to receive. That will be a great help in keeping us organized.
These tiles are meant to replace certain tiles in the main game, on either side of the board. This will allow for some very interesting match-ups. We hope you enjoy seeing these classic characters storming the battlefield as much as we have had working on their design!