I apologize for the really long delay! I had been extremely busy getting ready to move and I have some free time now to write to you. So the form you are looking at is called Sailor Saturn, the rest are Super Sailor Saturn, Eternal Sailor Saturn, Princess Saturn...etc.
You will first have to draw out the shape of your pattern on paper. There are three "feathers" of her sleeve, for the top one, begin drawing it at the edge of the paper so that you place it on the fold of your fabric - you will have to cut out four pieces total of the same fabric as your leotard and cut out two of interfacing for stiffness so that it retains it's shape. Add comfortable seam allowance to what you are drawing (I generally use 1cm), sew the pieces together, turn them inside out, and then attach the sleeves!
Make a few trial ones first out of cheap fabric (muslin) until you get them just perfect.
I really hope this helps and again, I apologize for the delay!