A
Azrael
Guest
*cough*
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Nomura has lost his creativity. He pretty much cameos and Easter Eggs the shit out of his other characters, games, weapons, attacks, etc.
This is just yet another reference to a Sephiroth based character.
Riku was a good person. A person who fought for the side of good only to be twisted and corrupted by darkness.
Feh.
What do you expect, it's Nomura