This paper model is the Way to the Dawn, the default form of Riku's Keyblade, based on the Kingdom Hearts II video game, the papercraft is created by Mickey103. There is also a Soul Eater Sword Papercraft on the site.
Like Sora's Keyblade, it is a Keyblade of the Realm of Light. Its form is based upon the Soul Eater, which it uses as an intermediary, and its name and design reflect Riku's nature as a being halfway between both light and darkness.
The Way to the Dawn is first seen in Kingdom Hearts II, when Riku arrives at The World That Never Was in order to rescue Naminé and Kairi from Saïx. Though it is technically a different weapon from the Soul Eater, Riku still refers to it by its previous name. Riku can equip this Keyblade within Mission Mode in Kingdom Hearts 358/2 Days. [Source: khwiki]
You can download this papercraft model template here: Kingdom Hearts II - Way to the Dawn Keyblade Free Papercraft Download