Reading Lands of Fire and Gold, I was struck by the similaities between the Kahone Warriors and the descriptions of Nagulism in The New World.
Oddly enough, neither of these Sorceries have been described mechanically. Since I don't think the Devs or the authors have an issue with the idea...
What are the odds they are holding on to it for a later book? It could be in Khitai (core or Nation book), 1868 or the Colonies.