He's never excluded himself, oddly enough. When approached by others as Lunatic, he always admits that he will one day need to atone, too. It's a matter of time...a matter of justice. And he vowed never to turn a blind eye, even if that eye should one day need to fall upon him.

So, what's there left to learn? ...Perhaps how much time is left? Admittedly, that is an answer he both desires and dreads.

In any case, he's not going to give Hisoka the pleasure of a direct response to those words. Instead, he offers but a polite tip of his head and a softly spoken, "I will leave my business card with the guard, in that case. When you're released," and he's not entirely convinced Hisoka was telling the truth about the release date, but because he doesn't know, he's ambiguous with his choice of words, "you may contact me if you haven't changed your mind."

He turns as if to leave, but does not move towards the exit.

Asks instead, "Was it worth it?"