This can be done as Modern fantasy or Medieval fantasy. It would only change the beginning, really.

Our story begins with a Well. A Well in a small town, where sometimes... people are thrown down that well. Nobody knows how deep it is. Nobody wants to find out. Nobody who goes down it ever comes back out, or even calls out from the bottom.

Your character, for whatever reason, be it as punishment for a genuine wrongdoing, punishment despite innocence, or a prank gone terribly, horribly wrong....
has been thrown down the well.

What will they find inside? Who knows! I guarantee this setting will go to some wild and wacky places, and has the potential to be a lot of fun!

If you decide to take a stab at this plot, please specify what sort of pairing you'd like to do when you request it.

Thousands of years ago, the gods numbered in the thousands. But their dominion was not forever, and foolishness is not the sole domain of mortals. Their war was bloody, long, and costly. Many were lost forever, and many fell from the heights of divinity. By the beliefs of the Trovian Empire, only a spare few ascended beyond mortal reach and became true divinity. The rest remain among mortals, in hidden places and deep ruins, straddling a line between cryptid, local legend, and fabled trickster spirit. The gods that remain are spoken of only by their titles, as speaking their name by any other than high-ranking clergy is blasphemy.

In the absence of the gods, Humans, elves, dwarves, and other races have inherited the world, and monsters have filled the spaces between.

Within this world, YC is a young adventurer at the start of their career, working as a caravan guard travelling a regular route between two cities. As they travel, they discover the caravan is being followed by someone in the nearby woods. When they confront this mysterious follower, they meet MC, a shy and reserved mage of some sort, who seems to be afraid of their own power.

What happens from there? WHO KNOWS?!
Well, okay, it's not a total mystery. Probably adventure and a somewhat slow-burn romance, and eventually saving the world!

NEW PLOT:
The Trovian Empire has been expanding in recent decades, and now an expedition across the sea has revealed a new continent, known as Ahmbra. A small settlement has been established known as Crownreach, or Ambition to the current inhabitants. The Trovian Empire's Ministry of Exploration is sending men and women to assist in the exploration and mapping of this new Trovian territory. MC and YC are explorers embarking on their own journey of discovery and adventure!

For some hints as to the aesthetic of the setting: pin.it/6cJKNtf

Tyr is a world of Swords, Sorcery, and Super Science. A world that has been brought to the brink again and again, each time clawing its way out of the pit. It is a world of cyborg wizards, burning brightlances, ancient evils, and powerful allies. I have several plots for this setting, including:
1. Rifts have opened across Tyr in a magical experiment gone wrong. Now the chrome cities and magical gardens are being burned to ash and rubble by a seemingly neverending wave of Elementals. Elementals not just of fire, water, ice, earth, and air, but of dreams, despair, fury, and joy. Our characters are part of the fight to penetrate the center of this outbreak and end it once and for all.

2. The world needs heroes. Now more than ever. The Searing Light cult has perverted the worship of the father star and conquered an entire continent, threatening to bring forth "fiery judgement" upon those who do not submit to their holy authority.
YC, as part of the resistance, has captured a Searing Light laboratory, and in the process theh have found a young woman, unclothed, huddled in a corner and terrified of you. Her hair short and white, her eyes entirely black save for the white irises. The scars on her body indicate magical and technological augmentation, but it is unsure how. Could she be the key to stopping the Searing Light? (Warning: this one will 99% certainly have a tragic ending.)

3. In the centuries after The War of Judgement (the events of Plot 2), things have been relatively peaceful on Tyr. But far to the north, a seer named Ojne has seen the future and knows that The Searing Light is not fully dead. Deep in The Frozen Heart, their centuries-old hatred has festered and grown into a force all its own, and it is preparing to complete its ancient purpose: put an end to sunrises. Kill The Father Star.

Ojne has selected one Northman of his clan to go forth upon a journey to stop what he calls The Dying Light, and has carefully selected a guide to help them on their way to the Frozen Heart, a long journey and an ocean away.

MC is the Northman (M or F), your character is the guide (M or F, preferring F)
This plot is WAY BETTER if we have multiple characters to join in as we go. :)

If you want some ideas of what this world might contain/look like, see here: pin.it/vqA9EkF

In the year 2278 humanity had claimed the stars for 150 lightyears in any direction from Terra, forming what is known as The Core. The planets of The Core formed a federal governing body with each inhabited planet as a member state, known as The Sol Federation. The Sol Federation represented a golden age of progress for mankind, but as with all good things, it was not forever.

Amidst the prosperous tidings of the age, as trade and commerce grew, so too did corporate power. Over the years, these corporate powers came to own entire planets, field militaries, and enter into secretive skirmishes with one another over land and holdings. The Sol Federation Defense Force, SFDF, did its best to stop these skirmishes, but could not be everywhere at once.

In time, the corporate powers began to style themselves as a return of the Noble House, issuing honors and titles to their subordinates such as "Scion" and "Knight," granting them new names to more properly be a part of the House's legacy.

As the Houses grew in power, their members joined the SFDF and held positions within the Sol Federation Councils, helping to keep a blind eye turned to their ambitions.

In 2404 the House Verrat Scion, Anton Vogel, put forth an official call to be declared First Lord of the Solar Federation. And when the other houses and councilmembers declined him, his forces moved into the Inner Core, rapidly conquering Terra and imposing himself as ruler.

The still-loyal portions of the SFDF mounted a counter-offensive later that year, freeing Terra from House Verrat, but with so many of their number defecting to the Houses in their efforts to eradicate House Verrat (an endeavour which proved successful), the SFDF could only firmly hold Terra itself. They were forced to watch helplessly as The Inner Core was divided up among the Great Houses, and The Sol Federation quietly died as the Houses began to squabble like children in endless wars for power, territory, resources, and technology.

It is within this Post-Federation Core that our stories take place, as two Great Houses once again come to blows over the planet Cameron IV in the Inner Rim near Terra, unaware that things are soon going to change forever.

[This is a mud-and-lasers sort of scifi. It's grim, but with just a touch of pink-mohawk cyberpunk thrown in to keep things from falling into Grimdark territory. If you choose to be a member of a House, you have full reign to determine their demographics, info, outlook, and aesthetic.)

For the aesthetic of this setting: pin.it/4OyEBm3

POSSIBLE PAIRINGS:
(Note: "House Agent" isn't like... a secret agent. It's a stand in for "someone who works for a particular House.)

Friends-to-Lovers with House Agents
Enemies-To-Lovers with Rival House Agents
Mercenary x House Agent
Mercenary x Mercenary
Cameron IV Citizen x House Agent

The Known World is a wasteland of broken spears and siege engines, ruined cities and rusting armor. The world was broken across the back of The Dark Star in ages past, and its corruption ruined most of the world. Only the power of the Honored Dead was able to push The Dark Star back into the depths of the cosmos.

Now, civilization exists in cloistered cities hidden among the wastes, where Watchers carefully investigate signs of corruption by The Dark Star, and root out any who may wish to herald its return.

In Stonehollow, a city carved into a hollow mountain, a mote of darkness is growing into a festering cancer deep below the gilded towers of the city.

PLOT:
Two Watchers find themselves in the middle of a growing crisis, with the Dark Star's hateful gaze drawing ever closer.

80 Years ago, mankind killed its mother.
During the Terracide, humans killed the earth by turning most of the organic material on its surface into graphite dust using weapons now known as "Chalk Bombs." The resulting continent-spanning clouds of graphite dust, plus the radiation lingering after the bombs, makes life on Earth's surface essentially impossible. To walk the surface is to have lungs filled with choking, radioactive dust as your skin is melted away by the lingering radiation.

Humanity is now forced to live beneath the surface, in the Arcologies. Cities carved into the stone of the earth, kept safe from the Chalk Bombs. The last vestiges of man now scrape out their existence from the dirt like ants.

In order to sustain themselves, the Arcologies must venture into the ruins of the old world, using ancient war technologies known as Frames.

You, in Arcology 7, are part of a rising gang looking to make its name among the faction politics of the Arcology. You may not be allowed to fight within the walls of Arcology 7, but out in the Chalk? Things tend to get hairy...