What is the unchanging factor that distinguishes a person?

There are many possible answers, but at least it’s not the face. Appearance changes too easily. With just a mask, one becomes unrecognizable.

If this were modern Earth, one could rely on fingerprints, irises, or various DNA markers, but here, this is another world.

A world where magic has developed more than science. So, there’s a unique way to distinguish people in this world.

One is magic power. Another is the soul. And the third is vital energy.

Of course, at the moment of death, even these dissipate, but with a …