He sees it, the unblinking lack of reaction, and doesn't know enough about Vanitas to understand why. Did he just not get it? Robbed of the fleeting satisfaction of needling him, Riku lets his eyelids fall and snorts through his nose. What is he going to do with him?

He's not Sora.
Riku won't lie to himself to claim he doesn't still experience that instinct to test his mettle, to be tested, but he's too tired and too scraped thin by grief to act on it.

"I mean at a distance," he counters, unhelpfully. "She didn't leave the lighthouse, once they finished hooking up the cables, we had company. What's it to you, Vanitas?" Pushing himself up out of the arm chair, he limps past the other boy, his jaw tight and expression just this side of openly irritated.

Looking to fill the void?
Make that two of them.