This is a nice and simple way of making a basic design of the hidden blades from assassins creed. (make sure you have the correct pieces. if yoiu have no bendy pieces, you can also improvise and make a blade of different pieces.) depending on the size of your arm, you will most likely need to upsize the white pieces to blue pieces and may need to make a longer blade and cover.

Step 1: Making the Armpiece (top)

First you make five (or MOAR) of these. (remember to move the rods up a size if you have large arms, unlike me) then put them together as shown in the next picture.

Step 2: Making the Arm Peice (bottom)

make five of these (again, make any corrections you need) and then put them together and link the outer pieces together.

Step 3: Connecting the Arm Pieces to Make the Arm Brace.

This is when you connect the white rods that were sticking out of the top piece to the bottom of the blue pieces on the bottom arm piece (as not very well shown in picture.)

Step 4: Make the Blades Running Rails

first you make these things, then you attach them to the sides of the bottom of the arm piece liek this. (2nd pic)

Step 5: Making the Blade

attach the bendy pieces to the 2 way V connector, and attach those to some orange straights in the back with a loosely fitting orange straight holding the white rod in between the two, which are attached to more orange straights, which have a white attached to their ends and another orange straight in between them. (just look at the picture and try to understand it.) if you have no bendy pieces, they you are forced to improvise.

Step 6: Making the Blade Sliders

you make these things and put the hole of each orange straight around the red blade runners. (only 2 of them.)

Step 7: Attach the Blade

now you attach the orange straights that stick out on the blades to the yellow blade sliders.

Step 8: Opening and Closing the Blade

to open and close the blade, you point it downwards and thrust your hand down to open, to close, point the blade up and thrust your hand down, if the blade is not coming out or moving at your will, slide the blade sliders around on the runners in unison, then check to make sure the orange straights that hold the blade to the sliders is in a parallel line to the runners, and then make sure it is in the center, if the blade moves up and down some, this is normal, i am currently working on that. if anybody has anything to add or something that is based off my design, feel free to post it and share your ideas.