why though? I don't understand. donating an organ is a good deeds right?

I think it is more in line that she will be in pain while her body parts are still connected to her soul. Like in some cases after Transplantation people retain donor's habits or even feelings

I heard when a heart transplantation happens the one receiving can actually gain the donor's memories or smt. So in a way they kinda become one? Ig it's similar to that, tho idk whether it's the case with other organs.

In this story, the concept of the soul is that it is connected to the body. Just like how the soul of Ms. A-young is still faded because the connection is not yet fully severed (it will be done after the funeral), the soul still has some connection to the body parts. Now, when an organ is donated, the soul is also contained along with it as it is part pf the whole body and therefore the soul will also be break part into fragments together with each organ. The girl (A-young) will feel the pain of each separation of organ because her soul is being separated along with the organ, with fragments of it leaving the main soul

so like being operated without anesthesia

i read that this was old belief something like that