AN: Because nobody can be alive and alone for that long without going a little crazy once in a while.
Bothering Monsters
It was not, Leon knows, that Merlin meant to be cruel. It was just that he had been alone a long time, and even before that, Leon understood that even when Merlin had been surrounded by people, he was still alone, in a way.
Even when Arthur was standing beside him Merlin was alone. (Although he always stood taller beside their king.)
Leon knows a lot about Merlin, now that it is just the two of them, now that Merlin was torn open beside Arthur on the fields of Camlann. He sees Merlin for what he is—a monster.
Not the sort of monster that Leon used to fight and kill indiscriminately, not something to necessarily be feared, but something to be respectful of, to approach warily. Like the dragon and the unicorn and the red lion, Merlin is precious and magical and not to be bothered.
Leon bothers him anyway.
He left Merlin to his own devices for a few centuries, content to be by himself and discover the ups and downs of immortality on his own. The first plague drove Merlin to Egypt and Leon to Venice, although both returned to England for various outbreaks through the 16th century. It was then, when everyone was dirty and tired and dying all around him that he went to see Merlin. What better company than a man who can't die? (Well… he's not exactly sure that Merlin is a man, not sure that he can't die, but he's not going to question the sorcerer.)
Merlin was back by his lake, safely tucked into a cabin with so many wards around it that even animals think twice. But Leon, while rubbish at magic (he gave it a shot in the 13th century but his heart just wasn't in it) could sense the stuff a mile away. He picked his way through the forest to the cabin, thinking about the past and ended up on Merlin's doorstep through instinct.
He's promptly vanished and re-deposited a few miles away.
Leon tries again a few days later and is sent to London. But the time after that he makes it into the house and invites himself for tea. Merlin is not kind and is not the cheery serving boy that the knight remembers. The tea cup is slammed in front of the noble and Merlin is petulant and silent when he doesn't cut Leon to shreds with his sharp tongue. The knight responds with the same harsh cruelty. He is old and wizened and has a bread that is ridiculously long; Leon feels younger and older than ever. He feels every one of his centuries sitting next to Merlin, drinking cold tea by the lake where Avalon and Arthur rest.
He knows that Merlin does not have to grow old—although this is the first time that he's come to see Merlin, it is not the first time he saw him. Merlin was young at the end of Gwen's rule, while Arthur's son lived and died, when Leon finally left, all his friends buried and all his prince's fallen. Merlin was young when Leon saw him last, 200 years ago in a skirmish on the Scottish border. Leon didn't know if the sorcerer was fighting for England or Wallace but he cut a proud, dangerous figure either way. Leon had been about to take a sword to the gut—Merlin saved him. Again. So he knows that man doesn't wish him ill.
It's probably, Leon muses, that he reminds the boy (he'll always be a boy to Leon) of the past, of Arthur and Camelot and everything that will never be again. Arthur might rise, but Merlin will never again fool anyone into thinking he's helpless.
It's very clear he's something else—something monstrous.
The second time he came for tea, Merlin looked a little younger but instead of lashing out with words, he used his fists and his magic.
It hurt.
And so the third time he trudged through the woods, Leon brought his sword and he hurt Merlin back. He was trained to inflict pain and, from a purely technical perspective, is much better at it. Besides he was left behind too, and after so many years alone and broken, he knows he is a sort of monster too.
He isn't vanished away after the blood and tea and stays for a few decades. Merlin is cruel to Leon, but mainly reserves his unkindness for strangers… and himself. At first they take out their pain on each other and Leon would be lying if he said the years were pleasant. But they weren't lonely.
Witchfinders come eventually, this time backed by a church instead of a king, and Leon and Merlin enjoy ruining them, breaking them. Cruelty is an asset in the world they have to face and an ally is indispensable. So they stay together. After the decades pass and the hunters forget them (or fear them) they leave the cabin and the lake. Merlin doesn't like to be gone long, but really, what's a hundred years or so when you have forever. The cabin vanishes into the forest, as invisible to mortals as the lake, and they go to Jerusalem. Leon is feeling nostalgic for war and that is where he was last a part of a proper army. Moving through the world, together they do a decent amount of damage and get a lot better at hurting other people. Their travels end in Grenada, where they go their separate ways.
This new war gives Leon plenty of opportunities to work through his issues of abandonment. He is monster. But then… then he is okay. It is a gradual change, he doesn't have a sudden epiphany, but he feels the sun and sees the sky and he isn't angry all the time. Then he isn't angry at all. He can look at his blood red cloak without feeling sick and mean, And the monster inside him fades.
It's a few decades before he finds Merlin again, once more at his cabin in the enchanted woods, by the magic lake. Leon has been better, has been married and happy, so when Merlin lets him in for tea and is cruel, Leon stays silent and still. Leon's bothering a monster—he knows the risks. But as a reformed monster (a reformed man) he also knows that the boy he remembers can be found. All he has to do is remember that Merlin is lonely and forgotten and waiting and cruelty is all he thinks he has left.
