[Polydamas]

As I think about it, the Night Riders' goal is different from the two basic types of traditional knife work:

- its not murder/murder survival where the offensive tactic is to stab in the throat/chest/abdomen as many times as possible, and the defensive tactic is to notice before you get stabbed, then to get away and if you can't get away take the weapon and break the man
- its not a duel against an equally armed opponent some distance away who care what onlookers think of him. Duelling for Neapolitans carrying folding knives with a 4" blade looks different from duelling for Filipinos with machetes with 20" blades but still the basic assumption is that the other chap has the same weapon and knows you are coming and that surviving with grace and honour is at least as important as surviving.

For their goal, I wonder if they need a martial art at all, as opposed to becoming intimately familiar with their weapon and how it moves and how to take bodies apart. These guys are already psychologically prepared to kill Things at close quarters, and chopping off arms/heads/tentacles is all about good weapon handling not fancy techniques.