| Majuba |
Hmm... not sure a "side of the road" works (by the rules), as permanency costs a lot of gold. Perhaps a bit of a mutation would make it work? A duergar who gets permanency 1/day as a spell-like ability?
Could work for an interesting encounter at low level, but I'd try to build in some good escape plans - dealing with the results of his actions could make for an interesting campaign, or campaign flavor.
Also - he could barter for his life pretty easily: "I'll make your spells permanent if you let me go!"