thats the thing about the death realm, anyone who is within the dealth realm, has the opportunity to get back to the surface if they find the portal out of it.
Meaning everyone inside the death realm is still alive until perma death comes to them, perma death coming from dieing of age, poison, or shot into the crystal.
However spending a long period of time in the deathrealm is bad, as time hits you all at once when you leave.
This being said, giving life should be possible, but ageing is not, until the surface is reached.