lets talk about what warfare looks like in that world
im only just getting to the war in book one but theres enough historically incongruous elements that my nerdbrain cant imagine it satisfactorily until i parse what all these soldiers and boats and weapons ought to look like
so its the second sinojapanese war / second opium war, either way thats rifles and artillery and ironclads
but the Mugenese come into war with cannons and rockets attacking city walls, fighting in full suits of armor with melee weapons---no references to handheld gunpowder yet. its like, Ming/Early Qing then. and yet, Mugen is industrialising, seems like
so consider industrial armor--closest analog is very late european plate that became cheaper (and better) than technologies combining lots of small pieces of metal--lamellars mailles etc.
when Japan invaded China the chinese were however wearing (those who were wearing armor) the steppe styles of the Qing, which feels out of place for Nikara that's under domestic warlords.
and how tf are the boats propelled? sails? steam engines? im trying not to use Fire Nation as my reference point