I'm not sure how to put this since i don't want to be an absolute meanie and talk bad about your entire model. I know i will first list off problems on the model and texture and then i will tell you how you can improve on them and make a more uniform and balanced sword. Alright? lets get started!!!!!

First off lets go over the shape of your katana. to put it bluntly the thing is crooked and contains some awkward geometry. to fix this issue all you have to do is work on the axis at all times. never deviate from the XYZ axis. you can lock mesh movements to an axis by hitting G for guide and then hitting either X, Y or Z to lock it to an axis. never move single verts one at a time as that causes Asymmetry in the topology and will make your model a nightmare when the time for texturing comes along.

now your vert count. this one is very simple it's high, very high at least its high for such a simple model. lets break down the katana model into 3 sections
there is the Blade, the guard and the handle. out of those 3 parts you need to create your sword. now for a katana the design is very simple. it is very streamline and realistic which means there are no curving bits or fancy extruding parts that would require more topology; Lets break down each part of the katana starting with the blade . the Blade of a katana is a slightly curved blade that becomes more extreme towards the tip. you can achive a curve like this by breaking down the blade into 3 parts, the bottom, middle and tip. at the end of the bottom make a cut into the mesh and drag the rest of the sword slightly up. do the same at the end of the middle. and now for the tip. to get the more extreme curve i just add in a fourth cut in the third section and drag the very tip of the blade up more then the rest. in other words set up a reference image within blender/3dsmax/maya and keep the mesh in wireframe mode so you can see through it. to do this in blender all you have to do is press N on your keyboard this will bring up a menu on the right hand side. scroll through all those options untill you see Background Images. click add image and locate the reference image on your computer.

next up we have the hilt, the hilt of the katana is circular and should continue off the handle. you can do this by extruding the top of the handle and scaling the mesh on all three axis at the same time. i recommend scaling it slightly and extruding it again to scale it the rest of the way to the perfered size. this gives a nice curve to the hilt. if you don't want a curve to the hilt then you can do a series of scales to make the hilt flush with the handle. to achieve this all you have to do is select the ending verts and Extrude them. as soon as you press that golden E button to extrude you must right click to cancel the scale now with them still selected just press that nice S key and drag it to the preferred size once that is done extrude it again and drag it out to get the thickness and you're done, one thing that i do is bevel the edges of the hilt. even tho this adds alot more verts i love the way it looks. and if you are working with 8 vert cylinders like i do it will only add in 16 extra verts which aint no mud on a pig

now we have the handle. this one is so simple i can explain it in a few words. use 8 vert cylinders drag the back of the cylinder to the length and you're done. just use the top of the cylinder to form the hilt.

and there you have it. one low poly low vert almost ready for gunz katana. if you follow these steps you can easily cut down on vert counts by 75%.

oh and one more thing. texturing. im getting tired of typing now so ima sum this one up in a few simple words.

Unwrap the model use high quality images (if you texture with an assortment of pictures) and thats it

now the client is almost downloaded so ima go play some of that good good for the first time in 3 years bye

-CJay