Also might be able to give him opportunities to be a "Don Corleone", the things a gangster will do generally fall into the following categories, sovereigns and nation-states do these things as well, but they use different words for them.

-Have meetings with other gangsters to negotiate territorial disputes or conspire against someone neither of them can take on alone. -Extort a tax from honest people in their territory (look up "Black Hand" on wikipedia, also extortion in general) -Have fights with other gangsters when territorial disputes could not have been talked out, often the fights are more 'symbolic' ending in truce or 'submission from', rather than 'annihilation of' the losing party. This is because if a gangster wipes out a rival gang without the resources to fully staff the rival's territory, a new gangster may move into it. -Making good on promises of protection when an attempt to extort a client is made by a rival party -Serving as a guarantor of an illegal (or if powerful enough, legal) deal between two parties who lack the strength to enforce it.

So...your super villain (SV) seizes some territory, and discovers smugglers running contraband through his territory into BGGG's kingdom. SV can handle this in a number of ways: -Impose costs on the smugglers by capturing and destroying shipments, thus forcing the smugglers to either remove him, or relocate their operations to neighboring territory (this could be beneficial, as he can gain favor with BGGG for solving his smuggling problem, while simultaneously creating a problem for his wealthy neighbor, who now has a smuggling problem) -Capture a shipment, introduce himself as "the new boss in town" and demand a meeting with the individual's boss (lord of the smugglers) --At this meeting, demand a percentage of the transit costs of smuggling (usually 20-30%) in exchange for guarantees of safe passage for shipments of contraband transiting his domain (other than symbolic large captures), and release for prisoners taken during accidental incidents (the town guard stumbles on a shipment and arrests everyone) --When the smuggler contacts him to say that someone else claiming to be a bigger fish has demanded tribute from him for transiting SV's territory, to have a meeting with that guy, and if a resolution cannot be reached, a gang war. --When the smuggler needs a loan to expand his operations, SV can offer one at extortionate interest (10% a month every month until you can pay me back the full sum I loaned in one big pile) --When the interest can no longer be serviced (possibly because SV upped his demand to 10% a week), grabbing the smuggler and informing him that SV is now running the show, and possibly asserting his dominance with a display of violence for the benefit of the (former) smuggler's underlings. --punishing a street thug who dared to attempt to hijack one of "his" shipments of contraband.
--Conspiring with a gangster in the capital city to scam the "BGGG's lawful stupid Paladin trying to stem the flow of contraband into the city" into taking out their rivals.