Okay so main tags for this one are: A/B/O, arranged marriage, Balinor lives, Dragonlord culture, Alpha Arthur, Omega Merlin, BAMF Merlin, Kilgarrah is disguised as a cat by episode 2.
Here is my rough outline for the Prologue.
Tells the backstory of how everything came to be as it is now.
Balinor goes back to Hunith several months after he fled to say a final goodbye and finds her pregnant so he makes the choice to stay.
When Merlin is around 5 or 6 Uther's men chase a sorcerer into Ealdor, basically burning down over half of the village in the process, and kill him and several of the knights recognize Balinor and make an attempt to capture him again. Balinor gathers Hunith and Merlin and they flee to the forest at the base of the Feorreh Mountains, near Engerd in Ascetir. They build a small shelter for themselves and set about finding ways to survive. Within a couple weeks several families from Ealdor who had lost their homes follow rumors and make their way to the same forest and they basically rebuild their village in that forest, Balinor and Merlin use their magic to help their crops grow and support their village until it's established enough to flourish on its own. A few other magic users over the years hear of Balinor's village (who has unwittingly become the Headman) and they begin referring to the village as Noddfa (Sanctuary in Welsh) and that becomes the name of the village.
Because of the need for the village and just because it is how all dragonlords live, Balinor teaches Merlin about his magic from the moment he displays it and teaches him what it means to be a dragonlord. Hunith and Balinor figure out pretty early on that Merlin and his magic are very different and more powerful than they've heard of before and Balinor has heard the prophecy of Emrys and the Once and Future King and begins to suspect that Merlin is Emrys but it isn't confirmed until a couple of years after founding Noddfa when a small band of Druids make their way to the village and feel the presence of Emrys and confirm Balinor's suspicions and also tell him that Arthur Pendragon is the Once and Future King. Balinor and Hunith both agree that it is too early to tell Merlin all of this and so they continue to raise him to know his power, but also how to hide himself, knowing he would eventually have to go to Camelot.
Merlin learns about Kilgharrah from his father and longs to free the Dragon. He is not yet a dragonlord but he swears there is a part of him that searches for the dragon and he can almost feel the heaviness of chains as though he were the one bound and buried under Uther's castle. When Merlin is 16, he overhears his mother and father talking about an uncle who lives in Camelot and whether or not it would be wise to send Merlin to see him or ask for Gaius to come to them and learn a bit more about healing magic as his was the best they had ever witnessed, but they're reluctant to send an unmated omega to a large city by himself, let alone a warlock without full control of his powers. Merlin begs to visit his uncle for at least a couple of weeks and his parents only agree once they decide Will and a druid who decided to make a home in Noddfa named Percival can and will go as his guardians which Merlin is annoyed by, but agrees so he can go.
Merlin eventually goes to Camelot and spends 2 weeks there with his uncle learning the basics of healing magic and making plans to come back a couple times a year to work on that magic or having Gaius come to Noddfa so they can work more openly. (He runs into Arthur and has his first meetings with him them same as in the show, but there is no banquet with Lady Helen yet, that banquet will be the one to welcome Balinor and his family to Camelot and Merlin will save Arthur then. Arthur also believes Merlin to be a beta because Merlin was covering up his scent to attract less attention) The last day of his trip to Camelot, Merlin goes to find the Great Dragon and introduces himself. Kilgharrah makes cryptic comments about Merlin and his future but because Merlin has grown up with his father and the druids saying vague things he just ignores Kilgharrah and presses on. Shows the dragon his own dragon soul, underdeveloped though it is, and Kilgharrah immediately takes to him and thinks of him as a baby dragon from his own family. Merlin talks Kilgharrah into making a solemn vow in the name of the Triple Goddess not to harm anyone in Camelot and to go straight to the mountains where his family lives and Balinor will give him refuge and then sets the dragon free. (No need for a specific sword, just lots of raw magic)
All of Camelot witnesses Kilgharrah being set free and although he does no harm, it sends the city into a tizzy. Uther starts to try and figure out a plan to protect them from the dragon because he's convinced that the dragon will eventually return with reinforcements (because he's not naïve enough to truly believe that he killed all of the dragons in the entire world) and burn Camelot to the ground as revenge for killing his kin in and around Camelot. He remembers the last dragonlord and how his men lost him in Ascetir nearly 10 years ago. He sends Arthur to find Balinor and ask for a meeting.
Arthur takes Leon and Kay with him and they go in plain clothes as sellswords and spend a few weeks traveling around Ascetir before hearing about Noddfa. It isn't common knowledge that Noddfa is magic friendly unless you hear about the town from another magic user. Most people just know it as a funny out of the way village full of people who keep to themselves and no one quite knows when it was founded or how it stays afloat so far out of the way. Arthur approaches the small village with caution and asks the first person he runs across, an young boy named Arrol, if there is a Balinor in their village and the boy very excitedly takes them towards a hut on the other end of the Village, slightly larger than the others and set just off of the village enough to appear separate while remaining part of the village. Arthur assumes Balinor must be the leader of their village. Upon knocking, Hunith answers the door and he asks to speak with Balinor. She tells him that Balinor is out in one of the caves with their son and Arthur asks for directions so that they may speak and Hunith tells him no, he must wait for them to return at sundown. Arthur agrees and leaves and waits in the center of the village, watching children play and keeping his distance so none of the villagers would think he was up to no good.
At sundown Arthur and his men return to Balinor's house and knock and this time the door is answered by the beta boy Arthur had run into in Camelot some weeks back and Arthur is immediately intrigued and also vaguely annoyed to see him. Merlin is panicked, but before he can ask what Arthur is doing there Arthur is kind of like "what the hell are you doing here? Is this a joke?" Balinor hears the commotion and comes over, pissed that someone is speaking that way to his son. Arthur kind of realizes Merlin is an omega and now the boy's Alpha father is scowling at him and he's like "oh, sorry, uh, are you Balinor?" and Balinor is like "who's asking" still upset.
Arthur apologizes and says he was just surprised to run into Merlin here of all places since he met him in Camelot, and he was also under the impression Merlin was a beta. Merlin tells his dad (in another language) to let up on Arthur and that he had kind of pissed him off when Merlin met the guy in Camelot. Balinor kind of grunts but ends up letting the knights in and Arthur delivers his message from Uther, apologizing and asking for Balinor to come to Camelot so they can work out something as an apology.
Balinor wants to say no immediately but with a glance at Hunith knows she's thinking the same thing he is, which is that they always knew Merlin would need to go to Camelot eventually and they had always assumed he'd have to go alone. If they can get this worked out, maybe they could be there with him and continue to guide him as he learned and protect him if things went wrong.
Balinor also has a suspicion he knows why Uther has sent word so shortly after Kilgarrah has come to them and he knows Uther needs him far more than he needs Uther so he tells Arthur that as things stand, he will never return to Camelot without some kind of assurance he won't be killed as soon as he steps foot in the city.
Arthur is offended that Balinor would suggest his father would offer him to talk and then strike a man when his guard is down, Balinor just kind of looks at him with pitying eyes and tells Arthur to talk to Geoffrey and Gaius and ask for records of the Purge and what he did to other dragonlords, to push them if he needs to, but to find and read those records. Then he tells Arthur he will consider meeting with Uther and coming to an accords, but it must be in a neutral location, not within Camelot's territory and their must be witnesses for an official peace treaty, or he won't even consider speaking to Uther, let alone setting foot in Camelot.
Arthur returns to Camelot worried and curious. He relays Balinor's message to Uther, then checks with Gaius and Geoffrey about the records that Balinor told him about and after some cajoling, they give him the records and explain that time to him. He finds that what Balinor said was true and Arthur argues about the sanctity of one's word and how as knights they must honor their promises and be forthcoming. And as monarchs, they should lead their people by example. Uther is upset at being lectured by his son but knows he is right so they work together and find a meeting place on the border of Camelot and Ascetir, in Nemeth. Uther will bring Geoffrey with them and some of his coucilmen to record the interaction and to officiate any agreements they come to and asks Balinor to bring a record keeper of his own as well as his family if he would like.
After Uther hears that Balinor has an omega son he starts to scheme of a way to make Balinor loyal to Camelot.
Arthur travels back to Noddfa and meets with Balinor againt. At first Balinor resists the idea of meeting Uther but eventually Balinor gives in and agrees to meet Uther under official banners. (This is when Merlin finds out his father is the Prince of a kingdom in the North, Uí Néill and there's a whole backstory to that, which makes Merlin a prince)
Arthur sends a missive to his father via messenger and stays with them in Noddfa for a week while Balinor arranges their party and then guides them to the meeting spot. Merlin and Arthur seem to rub each other the wrong way a lot of the time and although Merlin tries to mostly ignore Arthur, Arthur needles him in just the right way to get a pretty big snap back occasionally. Balinor doesn't take kindly to an alpha showing so much interest in his son and tends to keep Will and Percival close to Merlin. They bring Iseldir as their officiant.
Uther doesn’t like that their officiant is a druid and magic user because he doesn't trust magic, but Balinor tells him that Iseldir is an officiant from Ui Neill on behalf of King Darragh and Balinor will not even consider talking without him there. Iseldir promises not to use any magic on or around Uther or Arthur during their meeting to ensure they all come to a peaceful resolution. Uther gives Balinor a formal apology that doesn't actually apologize for anything about lying and trapping Kilgharrah and then hunting Balinor down and then talks about how there are hard times for all to bear witness to and Balinor is proven correct that Uther wants to talk and make an agreement so that Balinor will protect Camelot from Kilgharrah should he return, which makes Balinor laugh because he knows his son has already extracted a very powerful vow from the dragon not to harm those who would not harm him and in the few short weeks the dragon has made a home of their mountain, he has already come to see Merlin as a hatchling to nurture and protect and follows his commands as surely as he follows Balinor's. Balinor od course says nothing about this and isntead asks what Uther's idea is as neither of them trust the other. Uther distrusts Balinor because he is a dragonlord which means even outside of practicing the Old Religion, he has a dragon soul which is a type of magic. Balinor distrusts Uther because last time uther asked for cooperation and peace, it ended in disaster for him and his kin. Uther rambles a bit about how they each love their family and so the only way he can see for them to come to an agreement is bind their families through mating, gesturing to Arthur and Merlin. Arthur is appalled and although he doesn't say anything outright his face twists in distaste, Merlin grabs the back of his father's shirt and looks scared but also says nothing. Balinor says that this is something he needs to think on and asks to meet again the next day in the same clearing. Uther is disgruntled about having to spend a night outside his kingdom's borders, but agrees.
Balinor and Hunith gather Iseldir and Merlin in their tent where Merlin proceeds to freak out about not wanting to get mated and how he's only just full presented in the last year and how he doesn’t want to hide his magic from his mate and how annoying Arthur is until Hunith shushes him and hugs him and insists they need to at least discuss the idea together and how sorry she is that it's come to this. Balinor asks Iseldir if he knew this would happen and if he knew that Balinor would be made to sell his own son to "that blasted Pendragon." Iseldir insists that he only ever knew the prophecy as Balinor did, that it spoke of the great future that Emrys and the Once and Future King would bring together, how they are two half of a whole and that a mating, while not what they had originally thought, did make sense.
Merlin begins to insist that maybe he isn't Emrys and how can they be so sure that's him and as he gets more upset a storm starts to gather outside until Merlin scares himself into stopping ranting by lightning striking just outside their tent and making everyone jump and all of the adults give him chiding but pitying looks that pretty much say that yeah he's Emrys because no one should be able to do that just by getting upset and losing a grasp on their power. A small fire or explosion? Sure. But not full on effecting the elements and weather. Hunith reminds Merlin that Arthur is the Once and Future King, destined to bring magic back to Albion so even if he has to hide his magic now, he won't have to forever. And if he and Arthur are to be mated, he'll have the ability as Prince Consort to affect change throughout the land and make Albion a safe haven for all the creatures of the Old Religion.
Merlin is basically like, "that's great and everything, BUT HE'S AN ASS" so before he can take off on another rant about how annoying the "clotpole" is, Balinor breaks in and insists that Merlin is too young to be mated and he has no idea how to live as a consort and all the duties that entails and although he is learned and well read in magic, he knows nothing of the laws of men and surely him becoming a consort with no learning would only bring down Uther's ire to him and that would make Merlin unsafe. They also have no lodgings or means to obtain lodgings within Camelot. and Merlin is all like "yeah what he said"
Iseldir points out that Uther needs them far more than they need him and tells Balinor to have Uther write a law abiding contract that all parties will sign just as the king and queens do when arranging marriages for their children. Arthur is Prince of Camelot but Merlin is also royalty in his own right, not only is he Emrys, but Balinor was next in line for the throne of Northern Ui Neill (modern day Northern Ireland because I stan an Irish Merlin) before Balinor came to Camelot at Uther's request. Merlin asks what their house name was and Balinor tells him it was Ambrosius, which come from the dragon language and means "divine" or "immortal". Iseldir continues on and tells Balinor to add into the agreement that Merlin cannot be fully mated until he reaches his majority at 18 and until then they can do partial bonding with a scent bond and claiming bite from Arthur to Merlin (full mated bonds don't set until both partners give and receive a mating bite and consummate the bond) and Merlin can spend that time taking lessons and learning how to be a consort and that until then, they do not want to foster Merlin so they require adequate lodgings to stay with their son. (possibly add a scene of Arthur and Uther talking and how upset Arthur is to not have been consulted about this and how he wants to marry for love as Uther did with Ygraine and Uther pretty much tells him to get over it and to think of the well being of Camelot and it's citizens and how it's no different than arranging a marriage for land or an alliance with another kingdom. Arthur thinks to himself that although Merlin is an omega, he's still a guy and Arthur hasn't ever been attracted to a guy and despairs at being in a relationship where they need people on the side because it goes against his code of honor but doesn’t see how they can be happy long term without that kind of arrangement and he's basically just big sad because all of his expectations for a mate are dying in front of him and there isn't much he can do)
The next day everyone meets again, Balinor brings up all of the points that Iseldir made the night before, adding in that although he knows it isn't common for an omega to fight or train, in the dragonlord culture, as the oldest male, he's expected to continue his training and if Uther won't let Balinor continue to raise Merlin as he sees fit, they’ll leave right then. Uther very reluctantly agrees and tells Balinor that he cannot use magic in Camelot and that he has a close friend who is "reformed" and he can overlook the usage in the past for am oath not to use magic of the Old Religion from now on and asks about Merlin and Hunith not using it either. Balinor makes a pledge not to use the magic of the Old Religion and tells Uther that Hunith has never used magic and Merlin has not inherited his gift (carefully worded because Balinor still uses *his* magic which isn't technically magic of the Old religion, it's dragon magic, which is different enough not to count, and Merlin hasn't actually inherited the gift of controlling dragons yet, even though he has a dragon soul it isn't full realized yet and his magic is firmly cemented in the Old Religion so the magic he uses every day si not inherited from his father.) Uther asks if they can use cold iron to check them both and Balinor allows one of the knights to come over and press a piece of cold iron to the inside of each of their wrists and the only reason Merlin doesn't make a sound or flinch is because his father feared this would happen one day and has had Merlin practice touching cold iron for years.
After the testing is concluded Uther agrees to pretty much all of their demands but adds a clause about Merlin getting check ups regularly to be sure he can bear Arthur heirs which makes Arthur and Merlin both blush but Balinor agrees. Uther tries to get them to go back with them to Camelot now but Balinor insists his son will go no where near Camelot until the agreement is written and signed so he may be safe and Uther will not begrudge him the safety of his child. They agree to meet back in this clearing in a fortnight to sign the documents and for Merlin and Arthur to begin their scent bond and have Arthur bite Merlin in front of witnesses as well as have his first check up with Gaius before they all travel together to make it back to Camelot where Uther will plan a welcome banquet and announcement of Arthur's engagement as well as Merlin's introduction to court all rolled into one and he will call Lady Helen of Mora to come be their special singer.
Chapter ends here and next chapter is the episode The Dragon's Call.
Okay I think that's right. Just so you know, I'm copy and pasting these from my OneNote and then carefully reading through and editing or adding little bits ive changed in my head since originally writing this, which is a bit tedious, but is also fun!
Let me know what you think!