There was a weird modesty to Napoleon where he was very honest about what he wasn't capable of. He was, relatively, blessed when it came to looks and other skills, that he never felt a deficiency whenever he couldn't do something. The lack of ego in that regard was more do to the fact that Napoleon didn't like wasting time and energy on pretending he was more than he was.
So he knew he was about to get his ass kicked, but he knew he would be learning something from it too. As long as he didn't end up with a black eye, he'd call it a win.
Placing his feet in the appropriate stance and fists and arms coming up into his boxing stance, he explained with a smirk, "I know my face inspires intense emotions in people, but do please try to restrain yourself, Peril." And without much ado, he jabbed out toward Illya, trying to get a feel for how the other man moved.