Reading over the dev diary, HF isn't adding a new duel system, it's just letting members of societies use the same one from the war lifestyle.
The draconic lodge will probably have an additional possible mission to successfully raid a rival.
Masks are going to be annoying, since I'll need to make both human and dragon versions of the graphics.
They are changing personal combat so some rebalancing will probably be required.
What I meant was that if you allow a draconic warrior lodge for those who have the DLC then you have several sources of duels which kinda takes away the uniquenes.
So my idea was that with the DLC the raid rival action becomes a special action for warrior lodge members (as warrior lodges of different faiths can have different actions as the fetish shows).
The draconic faith still has purity as unique mechanic although that is rather passive. Imo what would be nice is if there were some annual decision for draconics similar the rammadan, summer fair or blot, which somehow affects purity or takes it into account. But that would probably a lot of event writing and wouldnt be a priority compared to other parts of the game.
People without the DLC and thus less duells can keep the current raid rival decision. That shouldnt be hard to code.
As for the masks, maybe it works like with the weight gain last week where missing portraits will not cause an error. The masks seem to be african religion specific anyway and that a dragon ends up down there would be rare (but not impossible).