The life span and aging process of a shadow is odd, so there are some rules about it.

- a shadow will not grow nor change in appearance once it reaches physical maturity

-a physically mature shadow can look between 17 and 60 years old.

-Shadows don't die unless they are killed by either someone else, something else or themselves. But even hurting a shadow enough for them to die is hard and there are no reliable ways to do so.

- The above rule can result in shadows being thousands of years old