So, basically Merlin is royalty from another country. He is also a transman with transphobic parents who wanted to marry of their "daughter" to some rich dude.
when merlin hits puberty, he experiences heavy disphoria with his female body and that's when his magic starts acting up. To match his gender, magic works kinda the same as Testosterone injections would (to keep it more realistic lol) and offers him the chance to grow up as who he truly is. The downside is, he has to run away from home.
years pass and Merlin figures out the dude he was supposed to marry was Arthur.
The day their marriage was set, merlin's parents visit Camelot to offer another daughter to arthur instead.
However they recognize Merlin as their "daughter" and get mad and angry at him for "being a disgrace" and shit.
and know who saves Merlin? You'd never guess, it's Uther.
Uther: What is going on here? Is your manservant being trouble again, arthur?
Queen: That is no manservant. I am ashamed to say this is my daughter.
Merlin : *ashamed* i'm your son
queen: you were born a woman! You were born our DAUGHTER! that will never change
uther: pardon, me queen X, but your son has been serving this kingdom loyaly, if incompetent, for years. royal or not, he has chosen his path.
queen: She!!!! it's SHE! Because SHE is a WOMAN!
*she keeps on ranting and misgendering merlin*
What curse are you under that you look like THIS now anyway?!
Uther: pardon me, milady. But has it ever occurred to you that maybe merlin was cursed before he was born?
Uther: being born into the wrong body.... sounds like a curse to me. my wife was under a similar curse once. temporary. For a few weeks only. The result was that she was close to infertile, even when we reversed the effects. She never stopped being a woman to me, but she constantly felt depressed about her body.
I can only imagine how awful it must be to be born with that feeling. and to be treated like it doesn't have an effect on him. I fathom your behavior just made it worse for him.
Queen: my daughter wasn't cursed
Merlin:.... *honestly about to cry*
uther: the boy sure seems to feel that way