Danmaku being implemented in some way might be interesting, but danmaku is also an inherently non-lethal system designed for Gensokyo and I'm not sure how well that'd carry over to something like Dwarf Fortress. I mean, we want to see things get pulped and smashed into gorey bits yeah?
Danmaku is supposed to be nonlethal*? I suppose could one could attach a stunning or knockout/heal (to be appropraitely harmful versus inorganics) syndrome to it. Then could walk over the knocked out goblin and pulp them.
* Bit doubtful about knives and nuclear fireballs and Marisa turning into a comet is flat out called as not danmaku, expect nobody really minds.
I'm not actually sure if the Secrets system even works in Fortress Mode to be honest.
You can discover parts of knowledge tree by pondering in libraries (takes about half a decade on average by my estimate). You can learn secrets of life and death from necromancers' books on that topic.
As far as I know, creating new knowledge trees would require hackery, and preexisting knowledge trees are at least included in string dump. I've yet to science the impact of preexisting high skill (such as with mechanics) on making discoveries, either. Then just can track if somebody knows some knowledge (stored under historical figure data, I think) in fort and if so allow (them) to progress the tech tree.
Non-innate secret knowers will only seek out learning secrets with goal of immortality.
Innate secret knowers can write them down, though. A classic example is dragon writing down the secrets of fire.
Haven't really looked into modding books, alas; though their actual vanilla gameplay impact is rather small.
As a civ, Koakuma already has incredibly high Regeneration and Disease Resistance, but I think for them to 'get away' without using metal armor I'd probably have to mod their actual tissues to be stronger. Which I might consider, since youkai/demons are supposed to be pretty tough... on the other hand, this means undead Koakuma are even more terrifying.
Well, in worldgen battles, currently gear isn't simulated, so if you were worrying about that don't. They'd fight just as well naked.
In fort mode...I think it is important to not flatten a sense of progression⁑, so if tissues get stronger that might be better to be gradual, maybe linked to magic use.
Alternatively, could improve their regeneration to limb-regrowing levels.
...Tbh, this is seems like matter of taste on where one imagines the Koa be on the scale of "dodgy resurrector" to "tanky invulnerable", i.e. do you imagine one could block a sharp axe swing with bare hand or would it cut away the hand like normal. Do what feels best, or even separate the koa into multiple castes if needed.
⁑ Sense of progression is not provided for me by multi-step chains like soap or steel making, though.
A possible issue I can see is it would make a really cluttered menu depending on how many things I bother to code in that can be transmuted - which is an issue since, technically, the Stone should be capable of doing the impossible like lead into gold, so in theory you could turn anything into anything but...
Or really general menu, if you make it kinda like jeweller or craftsdwarf and require stockpile links to control inputs.
Though there's perhaps the possibility to add reactions on the fly/use a manager(-like) menu.
I'm unsure if I can actually make anything that can mess with werecreature curses.
Werecreature curses require an intelligent not-not-living non-supernatural creature who doesn't have any of the default three preexisting curse types or is not already under a different species/caste transformation syndrome.
I don't know if you can have interaction effect: remove syndrome, though at least you can prevent it being applied in the first place.
The sun+wood idea is interesting, but I think if that was possible, it'd probably require DFHack and I'd have to figure out how DFHack works.
Uh.
Oh.
Yes.
...
Setting remaining growtime on a plant on farm plot to 0 is really simple, as far as coding scripts intended to be run with dfhack goes, but coding new scripts is still beyond typical end user of dfhack who just runs and maybe sometimes uses prepackaged scripts.
Now, something on that scale is something I may be willing to research into how to and help write. The "create a new knowledge tree" I mentioned above is on the level of "I don't even know if anybody has managed to tweak preexisting one" level, though I certainly have only barely looked into modding. (With mere glances, I know that warmist's df-mini-mods has done some really impressive stuff from the point of dynamic ease and modularity, for instance.)
Not sure if inducing berserk is a good idea in the context of Fortress Mode (as I think you'd have no control over who could drink it),
You could station a military squad into a room without waterskins and waterskin stockpile, brew the drink, have them equip and put the drink in waterskins, then watch them spontaneously start killing rest of your citizens next time they get a lil' thirsty.
Thanks for all the feedback and posts though! Sorry it took me a bit to respond to it all. I will probably hold off on any actual updates until the newest version of DF drops, because I THINK its supposed to be pretty soon from everything I've been hearing?
Toady has updated estimate from "october release is guaranteed" to "october release is 50/50", so it's probably going to be somewhere in november-december (and, jeez, I remember when I predicted a july release). Few weeks longer for bugfixes and catching up.