You know a movie or show with a secluded city, oppressed rough community? For DnD inspiration

Hi there, i got an underground city of cursed undead. Cursed by mages, who use them for assassination missions. The promise is: The curse will be lifted if you complete enough such missions. The undead in the city are self organized into different ranks. They run trials, to decide those ranks, so only the best group together for important missions so that they may be successful. A mushroom plagues the city. It is used as a drug to relive past memories. Many get addicted and crazy and have to live in the 'bad' half of the city. Can you think of some movie or show with those elements? Its not important that they are undead. They behave mostly like any normal community. Thanks a lot!