Riku

Riku is one of the main characters in Kingdom Hearts. Riku is a best friend of Sora. He may become a playable character in Super Smash Flash 2.

In Super Smash Flash 3
Riku was previously confirmed to be in SSF3 as a newcomer, along with Sora, wielding the Soul Eater. His design is based off of Kingdom Hearts 2. If he's officially confirmed to appear in the game, he may be able to use his alternate form of darkness.