Thank you! It was actually just made out of a boatload of white craft foam I had laying around, and hotglued together, then painted. The little jewels on the hilt were actually from my 3rd form Haseo cosplay- I just ripped them off and re-painted them, hot glued them on and bam! It was really, really easy.
Oh! I reinforced the back with cardboard. We happened to have a boatload of boxes hanging around so I chopped those up and reinforced the blade and handle. It's not the strongest thing, but it worked fine for a quick prop on a budget.
We happened to have a surplus since we remodeled our kitchen recently You could probably also use poster board! Or for a cardboard source you could get one of those display boards they have at craft stores for science fair displays.