(Assuming that helot MC wishes to claim the Laconnier throne for themselves by infiltrating Grand Shayard’s nobility) Refer to Havie’s quote: “A helot-born MC will not be able to “fake it” as a noble – they simply haven’t spent enough time in the presence of nobles to know how to pass themselves off as one. (Their option to infiltrate the nobility, if they go that route, will be as a freeborn tradesperson – if they’ve taken more time to get to know people from that class in Ch 2, they can pass.)”
(Or, assuming that helot MC claims kingship via axe-hefting/intimidation) Refer to Havie’s quote: “As the system comprehensively breaks down, the potential for “axe-hefting” change becomes much wider–and could be taken in either the “destroy the Four Olds ” direction you intend or the “co-opt useful values and features of the old system” direction that I think @Ramidel envisions.
The point at which a helot could declare themselves king of Shayard would be the point where social order had broken down so far that “king of Shayard” would be basically meaningless. But at a substantially lower (though still very high!) level of anarchy, it’s thinkable for a helot warlord to claim noble blood and have a significant numbers of people (especially merchants) in their sphere quietly accede to their claim – as long as said helot had managed to carve out a significant space where life and trade could proceed securely, and there weren’t better options locally on offer.”