I think you should report him to an admin or a staff or something (aye)but first... proof! I think he'll be reported somehow ^_^ I'm sorry for the trollers (I don't like them >:U)
How about recent visitors history and recolection of previous visitors? I know he was there the first time I was trolled, and I banned him at the same time he started trolling me. I stopped it while it was going, so I was lucky. He probably thought I was asleep, but I was awake and pissed that he was trolling me for a second time.