I think you meant "Foul demon" Also, keep blacking them IP's. But hey, that's a pretty damn impressive list of bans. I wonder what happens if someone executes something serverside and makes all your players execute it.
He duped and exploited. Those are not 'hacks' - they are exploits. Exploits may get you banned. Hacks will get you banned. That's the difference, so I guess you crawled through the eye of the needle.