Wow it looks awesome! Thanks for your efforts!
I will try that too! This is a very useful information, thanks for sharing it with the community!
Don't lose your hope! Maybe there is way and we just don't know about it or there will be an option in the future :)
Yes the wiki is still incomplete, but i will add it once i have more information.
To be honest, i don't really know what they are good for. I used it in battle and it just killed a random enemy. That's all i know so far, sorry.
Oh yes you were really lucky! These Demonblade monsters are really rare and i didn't even knew that you could get Tsurumaru in this form due smithing. Congrats on getting her!
We have no specific place were you can post recipes, so i think the best idea would be to post them on the character pages of the girls.
Ok i will try to explain it.
As you already know there are two types of demon swords. The ones with the colour pallete (i just call them demonblade girl) and the others with the different sprites (i call them demonblade monster).
These are the things i figured out about the difference between normal girls and demonblade girls:
They look totally equal to their normal form, except colours, expression and the mirrored images.
Demonblade girls can't be used as team leader, for work or in offering, but you can improve their sharpness in cutting tests. During battle they can be used in the support team or placed on the battlefield. But here you'll need to watch out, because they can retreat and try to escape, so you'll need another girl to defeat her. When defeated they will stay in your team but can't be used during the rest of the battle. I don't know if you will lose a demon girl if she manage to escape (i guess yes). I also tested if they still try to escape if their affection bar is filled. And yes they are still doing it, so i guess the affection bar has not much effect on their behavior.
The stats are equal to their normal form except the heat cost. They cost a bit more when placed and upgraded during battle. The only postive aspect i could find, is that they won't lose durability and don't need to be repaired after battle.
Demonblade girls can be crafted by using atleast one demon steel during the smithing process. They can also appear as boss on some maps and you will catch them if you defeat them, but they are rare and pretty strong. You can also convert them back to their normal form in the smithing area.
Now to the demonblade monsters:
They exist only as special demon version for a few girls. (Currently 6: Nagamitsu Kanna, Osafune Ataki, Nakigitsune Kuniyo, Kitsunegasaki Kikka, Tsurumaru Kunie and Hotarumaru Aso). They share the same qualities with the normal demon girls with few exceptions. Their stats are much higher and the skills are stronger and they have unique sprites.
Many of them can only be found on special places (Ryuguudou) or on Event maps. I think they are not craftable, except Kikka (my cousin got her after i gave her a random recipe).
So in conclusion i would say, the normal demonblade girls are currently pretty useless. Maybe i am missing something out, but from the things i know i don't see a reason why i would keep them. However the demonblade monsters are special. I would keep them because they are unique and strong and you can still use their support skill if you don't want to place them on the battlefield. Otherwise you can just keep them and see them like a sort of achivement or something like that :D
I think that was all i knew about Demon swords. I will also create an extra page for them in the future. If there are still unclear things, just ask and i will try to answer your questions.