Although Riku became a physical manifestation of Xenahort's Heartless, Riku continued to help Sora in secret. He was ashamed of his appearance and was able to gain the Way to the Dawn Keyblade. Riku was able to return to his original form when Ansem the Wise’s machine digitally sealed away Kingdom Hearts, later malfunctioning and then self-destructs.
Impressive cosplay and a magnificent Keyblade! I wonder what materials were used to make that? Thanks to Umbridge for sending this in!