A lifetime's opponent
Prompt: "I have a tale about fear, getting old, and a plague - a story no one knows."
I was special from a very young age. When I tell this to other people, they think I mean my peculiar personality, or my magic. It is more than that. I have asked every single mage I have met in my long life about it. I now know that I'm one of the very few aware of its existence. The only other one is Onni, as he became able to sense it little after having to flee with the two younger ones. But even he doesn't quite realize what it really is. He only knows it's dangerous and that he needs to keep himself and the younger ones out of its reach. It is whimsical. Each time I fail at destroying it, it looks for the children for a while, but grows bored after being unable to find them for some amount of time. If I stop trying to destroy it, my death will make it the constant companion of a newborn mage. Everyone around that newborn will only see it receiving an inherently strong luonto, rather than its rightful luonto alongside something else that shouldn't be there. If that newborn grows to have children of its own, it will attract actual powerful luontos to those children to avoid any discrepancy in power between parent and child. It will seemingly be a blessing, but in reality, the equivalent of a farmer coddling the very cows they intend to slaughter later on. I can't let this happen to another family. I have to be the one to make it vanish from this world, regardless of the high price of trying and failing.
Dad, mom, aunt Kaino, uncle Eino and aunt Tuuli were already adults when it first appeared in this world. They took a long time to accept that I could do magic. Veeti had always been an adult to me, just one who looked much younger than the others. I only really understood he had still been a child around the time I was born when he became the first in the family willing to believe in its existence. Some of the Old World machines told stories. The family had owned one of them when Veeti was younger, and it had once told him a story about a "witch" who would cast a spell on all the children of a village. The parents of the children, who didn't know of the witch, would mistake the spell for a sickness and didn't know what to do to make them better. Eventually, only one little girl in the village was not sick, because she was a witch herself. She was able to find the evil witch and kill her.
-Maybe the Rash is actually a spell like the one from the story, and that… thing you see in your dreams is the witch casting it.
It eventually turned out that some of those able to do magic could still catch the Rash, and that those unable to catch it weren't always powerful enough to qualify as mages. As for everything else, Veeti was strangely close to the truth for someone trying to make sense of his little cousin's strange dreams with a half-remembered story a machine had told him long ago.
The Rash has a mind behind it, a powerful one. It overpowers the mind of those changed by the disease, in addition to changing their body. It can't stop itself from propagating, yet is aware of its victim's suffering. It has tried to destroy itself in the past, to no avail. All it can do is pick a single mage, make them more powerful than they would have naturally been, and hope they find a way to destroy it. It decided to pick me, as I was to receive my luonto right when it had decided on this course of action. However, for something that wishes for its own death, it has a formidable survival instinct, that is impossible to beat once it kicks in. The challenge is hence to kill a being that is near-omniscient by human standards, with the price of a failed attempt being the death of a few complete strangers. The attempts that come the closest to success are those who frustrate it, and make it lash out, the most. If the person who dies of the Rash itself or one of its puppets is not a complete stranger to me, I know I've come closer than usual. Eleven years ago was the closest I ever got. It got back at me by causing an outbreak on the island on which I lived, only thinking of having my grandchildren "miraculously" survive in a moment of clarity, as to not completely run out of people to take away from me, should I fail because of one, tiny, easy to see mistake ever again.
Tuuri is gone. So I did come close enough that last time.
-It's really too bad. She amused me, thinking that she and her brother hadn't gotten sick in that outbreak because some benevolent being was looking out for her. But she was the easiest to reach when I had to pick.
I have to keep trying. I'm running out of time.