That is an extremely pointy sword. For the sake of safety, I urge you to make it out of something flexible & soft, such as layered up craft foam. Glue the layers together with spray-adhesive (do it outside) or contact cement. embed a hunk of a yardstick in the center, extending about halfway up the blade to give it strength. thin out the other end, and jam it into a pvc pipe for the handle (it should be a tight fit). Fill this up with epoxy adhesive to lock it in place.
For the "arm poofs", I'd use a plushy technique with them. Sew up a sphere (plans to sew a plushy sphere should be easy to find). Sew a sleeve into this (hand-sewing might be easiest here), and jam it full of polyester fiber-fill.
For the bell, it depends on if you want the thing to be functional or not. That is, do you want it to jingle? A functional bell would be made by taking some sheet brass from the hobby shop. Heat it on your stovetop on high until the thing turns funny colors. Let it cool (this softens it). Cut a circle with a compass and tin-snips. hammer it with a plastic or wooden mallet over a wooden or solid-plastic hemispherical form. For the bottom hemisphere, form the sound-hole by drill 2 holes and Dremel or hack-saw between them.
Turning the edges so they lock together is tricky work. You may be better off just brazing it. Put a marble in one hemisphere (don't forget this!), and lock the pieces together on a sturdy vice. You might need to hammer or bend a bit to get the edges to meet all around. Brush the seam down with flux (I just use the stuff from the plumbing department). Then take a piece of brass wire, and bend it in a circle. Put the wire around the seam and solder one end in place. Pull the wire tight and clip off the excess, so the ends meet, and solder the other end down. Heat the far end (away from your tack-soldering) with a torch and allow solder to suck into the seam via capillary action. Do this all the way around. Solder a piece of brass onto the top of the bell so you have something to tie it to. file, sand, and then polish the surface smooth with rubbing compound (got mine from the automotive store.) It should be nice and shiny at the end of all this. To keep it shiny, wash it in soapy water, rinse it, dry it, and then spray it with 2 coats of clear lacquer. You can skip this step, but you'll need to polish it before wearing it with something like Brass-o polish to restore the shine.