When magic builds up
When the Shrine of Aralican dissapeared, the people of Morlea could no longer go there to reveal any form of magic their children might have. For many, it wasn't a problem. Powers went undiscovered, but it was not harmful to the individual who held the potential of magic. However, if a person had great magic within them, they could get sick. The symptoms come slowly, first people get nauseous, then a headache which would get worse over time. Then fever, and at last, the magic builds up. The ones with a lot of magic will get a bigger burst when the magic is finally released. Some people die fromt the damage of the burst, others barely notice and they survive just fine.
The condition is caused by natural occuring magic within a person. The magic has to be powerful enough to influence the person physically, if there is too little magic, the person will not get sick.
At first the individual will get nauseous, this is not an alarming symptom as many get nauseous often. After a while the person will get a headache, this will also start out like it's normal. The difference between this headache and normal ones is that the one caused my magic will persist for weeks, and will increase in pain levelsl After that the person will get a fever and the fever will only get worse, but faster than the other symptoms did. Around 5 days after the person gets the forst signs of a fever, the body will have no defenses left and the magic will burst out, damaging the body of the person as well as their sourroundings.
There is no known treatment, one can only try to get the magic to reveal itself in other ways. The only way which works no matter what is visiting the shrine, but the shrine has vanished.
If a person has large amounts of magic then they will usually die from the blast. The more magic the more powerful and damaging blast. If a person has a lesser amount the sickness can seem like a flu and the damage will not be anywhere near fatal.
Everyone who possess magic in bigger amounts get affected by this. If there are many magic users in a family, the chance of the child having magic is higher too.
If you have found a natural shrine or just been to any working shrine after the child has turned 17, the magic will be let out and be usable by the child. If this does not happen the symptoms will come within a few months to a year.
The condition has always been known, this happens whenever there are people who have no way to access a shrine.
When a person get to the final stages, they are removed from anyone else and put into the forest. The burst is lifethreatening to others, but up until the fever sets in they are cared for by loved ones.