Soul Eater

The Soul Eater is Riku's weapon in Kingdom Hearts: Chain of Memories. It was made of the darkness inside his heart, "forged" into its sword-like shape by Maleficent's magic. The Soul Eater is also used by Vexen's Riku Replica. World of Chaos even had a double bladed pole arm version of it. It looks a bit like a dragon wing. It eventually turns into the Way to the Dawn.

Its name is derived from an ability attributed to the Dark Knight class in the Final Fantasy series, in which Soul Eater drains the HP of the user to initiate an extra-powerful attack.