Shadowgrave City, Kanto
The foundation for this massive metropolis was laid down about a thousand years ago by a corporation who originally intended to construct a self-sufficient factory town, manufacturing trainer goods such as potions, pokedex, or pokeballs. Over the decades that followed, however, the city soon began to fill with chemical laboratories, foundries, and plants producing all sorts of goods to meet the demands for consumer goods all over Kanto and beyond (where do you think those trainers get all their clothes, equipment, and other essential goodies? SHADOWGRAVE!). The city's population exploded, eventually surpassing twenty million souls residing in what was the largest city in the world.
The housing and sanitation—along with refurbishment, crime rate, and urban organization—soon became serious problems that would plague the city administration for years. The sheer size of the city made it impossible for a wide-scale demolition and reconstruction, worsened by the shortage of police manpower needed to keep the city from descending into lawlessness. Just when the overcrowded and wild city seemed to have ran out of options, one administrator came up with a solution that was as simple and cruel as it was—eventually—effective: he proposed simply that another layer of city be built over the old one, as to provide more room for the people and give the rich a chance to get away from the rapidly deteriorating environment. The resulting project was a stunning success, relocating more fortunate (and richer) citizens out of the slum-like conditions. The most destitute ones were left at old city below as a "skeleton crew," separate from the orderliness of the upper level.
The construction of the second tier was an important turning point in the city's dark history. Not only was the population allowed grow indefinitely, but administrators now also had a model plan to follow whenever things grew out of their control. They could simply build successive layers of cities over the chaotic masses, and start anew with the best and the brightest. For all its wealth, the Shadowgrave City—as the rulers would say—simply did not have the budget for the rest.
Current appearance & structure of Shadowgrave:
A thousand years later, Shadowgrave City is now a conglomeration of layers after layers of urban structures piled up on another, connected to each other via huge lift tubes that can transport dozens at once. No one knows exactly how many levels exist, only that the city can extend down for miles below the ground. Each level has its own apartments, shops, streets, etc.—pretty much like any average city. On top of all these layers stand about a dozen massive spires that reach high into the clouds, inhabited by wealthy noble houses that own virtually all major businesses and factories. Immediately below them, the middle class population lives on the first few top layers of the city; below them lies the vast factory levels where the lower class families live and work. In short, the higher up you go, the nicer the environment gets—not to mention finding wealthier people.
Below all of this lies the undercity.
Undercity is a collective term for lowest inhabited levels with barely any commodities such as running water, electricity, or heat. Yet, millions still call this place their home all the while fighting tooth and nail for limited resources allotted to them. The food and other necessary supplies arrive regularly from the upper levels (just to keep the people from rioting), which are by no means plentiful or in good quality. The living conditions are dismal and squalid, as most of the sewage and garbage from the upper levels end up in the treatment and recycling plants situated here. Crime is endemic, and gangs constantly fight for territory, resources, and prestige. Simply put, undercity is a dog-eat-dog world where the strongest, the smartest, and the luckiest individuals can survive.
Throughout the city's growth, the people have constantly migrated ever upwards, even the poorest lot, taking up the place once occupied by the wealthier people once they themselves had moved up. This trend has resulted in many lowest levels of the undercity being entirely deserted; no one knows what lies down there, and only the bravest and the most desperate ever venture down here to explore. Rumors speak of hidden riches as well as mazes of tunnels that lead nowhere, teleport panels that can take you Arceus-knows-where, and some malevolent forces lurking in wait in the darkness.
The mobility between these levels exists to some degrees, if not very difficult to achieve; only few families accumulate enough money to move out of their surroundings. The spires themselves are off-limits, however, privy to the rich nobility. The movement out of the city is even more stringent and highly regulated by the police, since large outward migration can jeopardize the day-to-day maintenance of Shadowgrave city. The civic authority is nominally in the city government, but the real powers behind it are the noble families of the spire, who uphold an authoritarian regime via their control of police and private militia forces.
(For a better mental image of Shadowgrave, just think of New York City and Detroit mashed in one, only a thousand times bigger, messier, grittier, and more crowded. Partly inspired by the hive worlds from Warhammer 40k universe; (go look it up ))
Pokemon in Shadowgrave:
Over the centuries, the growing cityscape and the desolate environment had—amazingly—given birth to a unique ecosystem of wild pokemon living in Shadowgrave itself. Clearly, one would not find every kind of pokemon just living around in the city; only certain kinds that had managed to adapt to the urban setting survive and even thrive here. High up in the spires, wealthy nobles would build biodomes to import and breed any pokemon they would want, either to cater to their own egos or just to pamper their children. Around the lower levels of the spire and the top layers, the most common pokemon are Growlithes and Houndours used for police duties, as well as some wild bird pokemon and rattatas scavenging for scraps. Undercity, however, is the place where most Pokemon thrive. Sewers are haven for poison pokemon, for example, while electric and steel-type pokemon are attracted to subterranean cables, abandoned factories, or junkyards. Rattatas, Meowths, Spinaraks, and Zubats are just as common to the undercity streets. Furthermore, some rarer Pokemon originating from the upper spires occasionally find themselves in the undercity and breeding, either by escaping or by being abandoned by their owners (Examples include Glameows, Zigzagoons, Machops, Growlithes, or Houndours). Meanwhile, the deepest abandoned levels are infested with ghost-type pokemon, making the trip there even more hazardous. Grass or water pokemon, due to lack of suitable environment, are virtually nonexistent in the undercity.
The inhabitants of the undercity have over time learned to live alongside the Pokemon, sometimes capturing them and training them for their own uses.
(Rule of thumb: just imagine your typical urban pests, like pigeons, cockroaches, rats, raccoons, stray cats, stray dogs, spiders, centipedes, and the ilk.)
Gutter Runner(s):
A gutter runner(s) is a slang for an individual or a group of people who performs all sorts of jobs and services in the undercity to make ends meet (aka "hustling"). Gutter runners' main job is to venture down to the deeper abandoned levels of the undercity to explore and scavenge for any items of value, which is a rather dangerous task. Other activities they engage in include and are not limited to: scrounging for scrap metal in the junkyard, smuggling and transporting contraband goods, delivering messages across the city, stealing, extortion, hiring themselves out as bodyguards, carrying out dirty deeds on behest of wealthier men in power, or simply doing odd chores around the community.
Except for the most talented individuals, most gutter runners band together into several gangs that essentially operate as guilds, each with its hierarchies, traditions, specialties, and objectives. Life in these gutter gangs is a hazardous one, since gangs must fight one another for turfs and resources. Gang members are mostly drawn from teenagers of the undercity population with various motives for joining, some for excitement, others to make ends meet and to support their families. All gutter runners carry at least one pokemon around them both for personal protection and to make their jobs easier.
Note: I need OCs! Feel free to use the info above as a reference guide….