Had an idea- not sure we’re even getting Japan in the future but I thought this would be fun and unique:
Similar to the Mongol Khan, the Japanese could have a Shogun that can either “drop” or specify an area to smokescreen for 6-10 seconds. This would stop ranged units from being able to see/attack into the smokescreen force melee combat or mangonel fire into the smoke.
I think it would be fair if both Japan as well as their opponent are unable to see into it. It would be akin to stealth forest vision.
Like i said, this could force melee engagements, halt an attack temporarily, force mangonel fire into the smoke (or not depending on if it’s a bait), allow melee units to close gaps to siege units or backline archers, or cover retreats.
If anyone reads this, let me know what you think.