Buff Riku of Darkness

Buff Riku of Darkness appeared after the death of Buff Riku, because of this people assumed he is his Heartless, which Niki confirmed after Justin said "And now.... I am black" and Niki replying with "Shhhh, it's heartless mode." When Buff Riku of Darkness first appeared he said "You used me. You exploited me. I fought your enemies. I made your memes the quality only gods would hope to achieve. I stood by you. You beat me like a dead horse. And now... I am back. And I promise you, I have not come in peace. I will destroy you. I will eviscerate you. I will grind you all into powder and use you as a protein shake of darkness. You shall suffer. This group will be no more. You will never win. I. Am. Your. God!" It was revealed by Niki that when Buff Riku of Darkness dies his Nobody will appear.

Powers
His powers are unknown

Weapon
It is unknown if he uses a weapon or just punches

Trivia

 * Even though according to Niki no arc is forced, he stated in the comments that "Yes, but but it is not only forced, but also Nomura inspired we have reached Kingdom Hearts levels of story telling"
 * 'Fragments of Sorrow' is his theme