Samurai Shishou(Samurai Master) is a 3rd person fighting game based on the samurai stories.For that,we made an original one for our game.
As I promised,here are the main weapons in the game.They will be used by enemies as well but maybe other textures.
I will add to the Yari(Spear) a flag with the Shogun's seal,the three leafs for the enemy guards.
Katana Model
A katana has a curved blade and a longer hilt. this looks more like a wakizashi-sized ninjato. The issue with the blade curvature also appears to be in the nodachi and wakizashi models.
The wakizashi and nodachi are slightly curved at the back of the blade as it seems, I'd recommend giving the blades and overal larger curvature going through the whole blade's length and giving the edged side the same curve so the blade is more consistent in width.
I'd also recommend rendering with some added lighting, it's rather hard to see the models you posted.
the hilt looks a little small, i noticed a katana is more like a hand-and-a-half sword, while the hilt there looks like it would be only used with one hand (like a longsword)
Also, the blade appears to be too thick, it should be just about the same size as the hilt (since the blade goes down into the hilt, like with any sword/knife)