"I am to blame. When I met Riku the first time he still had the appearance of a boy. Probably because he had such a strong heart. I asked him to find a young man named Roxas from Organization XIII, and bring him to me. When I told him it would help Sora awaken from his slumber, Riku left without a word. He fought Roxas. And I can only surmise Riku lost that fight. Riku must have realized then: to fight in the realm of darkness, he would have to immerse himself in that same darkness. And when he did... you saw what became of him. When Riku brought Roxas back to me, he was introducing himself... as Ansem. If that was what it took to awaken his friend, he was ready to live in darkness. Riku was the victim of my revenge... Oh, how my heart ached. I could only laugh to hide my shame."

(AN-the longest quotes always come out the best imo)