Unless he joins your channel, he's not bothering you, anyhow. If he's joining your channel, you can ban him based on his host/IP information, and then you don't have to deal with him anyhow.
If he's really a problem, you can also talk to an IRCOP and provide the logs to show what is going on. Perhaps you'll find an IRCOP willing to keep an eye on the person and maybe kline him.