I highly doubt that he expects you to try to kill him. What you told me of your actions last time means it would be obvious to him that you know killing him outright wouldn't work.

[He's just ignoring the moral issues of all of this for the moment, focusing on the practical ones, because they're the only part he thinks Maketh might respond to.]

He wants the attention and the challenge, and you'd be giving him exactly that. Do you really want to reward him for what he did?