It sounds like he's talking about Sora, Donald, and Goofy, in that, he was just talking about them moments before he said "Wait... else." But he could also be talking about everyone there in the castle.
In Days, we're told that he was sent there to kill Zexion and the traitors, who we're lead to believe are Larxene and Marluxia, but it could be his interactions with all of the people he had interactions with up to that point.
Manipulating two traitors into believing he was on their side, aiding Namine help Sora, killing Vexen in a means to further manipulate Sora, and by that point he had already manipulated the Repliku into killing Zexion. It could have been all that that he found pleasure in.
Also, he wouldn't have been mentioning Roxas, as he had hardly known Roxas when he left for the castle, right? I'm not exactly sure on that last part, but it's still something to think of with the posed question.
