if you've played touken ranbu or kantai collection, you're probably used to the kind of crafting system where a certain amount of resources has a chance to give you a certain sword or ship type, with some classes being rarer than others

 (the crafting system is 20-55 stones put in gives you a chance at tantous, 20-70 gives you a chance at wakizashi, 20-85 gives a chance at uchigatana, 46-99 gives a chance at tachi, and 69-99 gives a chance at oodachi)

(you might see demon girls as bosses, you can get them as a drop if you beat them, you can purify them in the forge with heat to get them back to their normal forms, more heat is a greater chance at success, if you fail nothing really happens)

shinken also has a rarity system based on how much heat you put in during crafting (i've heard 18k heat is the magic number for higher chances at rainbows but yeah)

what does that mean? well, basically, the rarities are color coded and go blunt sword(namakura/green colored)->wazamono(red colored)->ryo-wazamono(silver-colored)->o-wazamono(gold-colored)->saijo o-wazamono(rainbow colored)

if you're curious about what these names mean check here

but anyway. swords that are lower rarity cost less to deploy and have lower stats, but level up faster 

you can rank up swords that are lower rarity using the cutting test system


in it, you test your sword's strength on items once they reach a certain level: these items are dropped from stages or can be made when you get buildings in your citadel to a certain level (send girls to work at them to level them up, stay away from the option farthest to the right because that destroys the building, more buildings/higher-level buildings raises your heat cap)

once you have gotten far enough (trained three times) with your sword, their skill will be unlocked.

once you finish all of the training, you rank up and then can train at a higher level (for example: once a blunt sword finishes all the training shown in the screenshot, their color will turn red because they've ranked up, and they will be able to train in the red area)

one thing you really need to watch out for, though: the materials for higher ranked swords drop in higher-leveled areas, and not having access to skills can really hurt 

what it's recommended to do is instead of leveling up, say, a rainbow-ranked sword from level one, get a dull sword of the same type, level that one up, and then fuse that sword with the rainbow-ranked one so that it will gain that one's exp


click the thing in the middle to fuse them together

at this time, i don't know if the swords can share exp when they are fused with swords that are not the same girl

and i've heard unconfirmed rumors that if you fuse a sword that already has its skill unlocked with one that does not, it'll unlock the skill for the sword it was fused to even if the sword that doesn't have it unlocked is not high-level enough to unlock it through training

this is all unconfirmed, and this is a very basic guide, so if anyone would like to add onto it or make their own better one, please let me know