How lucky does someone have to be to be reborn?
How lucky does someone have to be to transmigrate?
One in several billion?
No. If we are counting, the denominator is certainly not limited to the number of people on a single planet.
Perhaps it includes every intelligent animal, or even every living thing, whether intelligent or not. Perhaps it includes every stone and metal, or even every atom in the world.
Perhaps even that would not be enough.
This is something whose very existence is uncertain. No matter how infinitely large the denominator of the odds may be, beside the numerator it still seems so unreal.
P.S. I'm too lazy to think of a synopsis. This will do for now.