A tale of a land called Adia

There was once a land called Adia. When the kingdom of Adia was founded, a spell was casted.
The spell in question was that every time someone did something wrong, they would lose a piece of their soul. A minor wrongdoing, such as lying, would make one lose a tiny piece of their, while something really bad, such as a murder would make them lose a larger piece.
If one lost all pieces of their soul, they would become immortal and live eternally as insane, haunted by nightmares and hallucinations.
A little girl named Ria lived in Adia in a cottage with her mother.
One day she was arguing with her friend, and got mad enough to push her. Ria only realised what she had done when it was already too late. The friend ran home crying, and Ria could not think of anything else than the fact she just had lost a piece of her soul.
That night she had a horrible nightmare, and woke up panicked. She stayed awake for a few hours, waiting for sunrise. When morning finally came, Ria went to her friend’s house to apologise as quickly as she could.
Ria had a grandmother named Ida, who would visit their house very often. Ida even had her own room.
Ida sometimes woke up in the middle of the night, sweaty and screaming like a pig that was being slaughtered. She would occasionally point at random spots or ask: “did you hear that?”, even if nobody else saw or heard anything out of the ordinary. Whenever Ria asked her mother why grandma behaved like that, she would act awkward and tell her that it was due to old age.
One day Ria’s mother had gone to a nearby city and left Ida to babysit her.
It was getting late and Ria went to her grandmother's room to ask her to make some food. She rarely went to Ida’s room, as her grandmother didn’t like being disturbed. Ida was sitting on the edge of her bed, staring at a wall and mumbling, as if she was having some sort of a conversation.
When Ria knocked on the doorframe to get Ida’s attention, she was startled like someone had just fired a gunshot.
Ria informed her that she was hungry, but before leaving, she noticed a framed photograph on the bedside table. The photo seemed somewhat old, and after looking at it for a while, she could recognise her young mother and grandmother. There was also some other child that Ria did not recognise at all.
“Who’s that?” Ria asked, pointing at the child.
“He was your mother's friend who lived near us. His family moved out of the village a couple years after this photo was taken. But let’s go downstairs and cook now!”
When they were descending the stairs, Ida tripped and fell. You’d expect that fall to be enough to kill an old person, but Ida was just fine.
A few months later, Ria’s mother had to go to a nearby city again for a few days, so she left Ria at her grandmother's house.
Ria noticed that one of the rooms had a door that was locked from the outside. When she asked Ida about the door, her answer was: “that's an old storage room and you're not allowed to go there.”
“But why?” Ria asked.
“It’s messy, you could step on a rusty nail or something worse!”
One night Ria woke up, feeling cold. She thought that maybe she could find a thicker blanket in the storage room, but she didn't want to wake up Ida, so she put on her shoes, thinking that those will protect her from any rusty nails lying around.
After several unsuccessful attempts, she managed to pick the lock on the storage room’s door, and opened it.
The room behind the door didn't look like a storage room at all. It had a small bed, a closet, and some toys on the floor. Everything was covered by a thick layer of dust, and there were no rusty nails anywhere. Ria noticed a blanket on the bed and took it. But there was something that caught her attention under the blanket.
It was a child's dress, which looked unnervingly similar to the dress the boy in the picture was wearing.
The next morning Ida noticed that the lock on the door was unlocked. She gave Ria the same lecture that everyone who grew up in Adia has received multiple times.
“Ria, you picked the lock open even though I clearly told you to not go there. You could have woken me up and asked me to get a blanket for you, but now you have lost a piece of your soul forever. This spell was casted in the very beginning of everything and has been maintained by our rulers, who have never lost a single piece of their soul, for the welfare of the people of Adia. All of this is for your own good.”
Funnily enough, after Ria picked the lock, she slept well without nightmares, and the day after that went well too.
A year later, Ria was in her home with her mother and grandmother, when someone knocked on the door loudly. Ria’s mother rushed to the door and Ria followed her.
Behind the door there were six armored Adian soldiers asking if they knew where Ida was. Ria’s mother gave a truthful answer, which happened to be in their kitchen.
The soldiers captured Ida and transported her to a nearby castle. After a while Ria discovered that her grandmother was accused of killing her son among a plenty of other horrible things.
The judge started to think that after doing so many horrible things, Ida would have lost her soul completely and would thus be immortal.
There was only one way to find out if she had lost her soul, and that was by trying to kill her. If she survived, she would have lost her soul and therefore she would be guilty. Even after half an hour underwater she was fine.
The people I heard this story from said that Ida is still held in that castle.