Question Reincarnation + Rejuvenation Methods' Limitations?

What are the limits to Magic, Gadget, Devise, and other methods of life extension?

...Magic should be limited by Essence supply.

Devises and Gadgets both are limited, by stability and Devisors/Gadgeteers to make the devices in the first place.

Devises are limited by their non-reproducability...

Gadgets are limited by their complexity, as if it's too complex, mass production is basically impossible without a tech increase in other areas.

Dr. DNA used Devises/Gadgets and magic to transfer the souls of his Animen subjects into their new bodies, so that might be possible using Devises or Magic alone...

Magical reincarnation has been seen with Shelly Carson, her soul being captured in a Koschei Chest and inserted into a new body. However, that new body was required to be genetically identical to her old body. Could rejuvenation be done this way?

Magicians also have Youthening potions, and whatever Circe does to keep being alive...

Jobe's Drow Serum and similar things would also work as Rejuvenators...

Off the top of my head - life extension mentioned in the WU:

Circe has been alive god knows how long. Several other mages have been described as looking younger than they are, although I don't recall others who have exceeded a natural lifespan. Actually, looking young and beautiful seems almost standard issue among high level female mages (although my memory may be exaggerating). The Green Witch used a Fountain of Youth, and there was one guy from The Angel of Hell's Kitchen who was turning into a baby.

High level exemplars often age slowly.

Several origins have caused age reversions.

Shelly Carson was re-ensoulled.

Ayla talked to one bio-devisor who's family has a feud with a villain who keeps coming back from the dead, but nobody is sure how.

Mimeo uses borrowed Regen to become younger, but he reverts faster than normal once the power wears off.

Mephisto has outlived a natural lifespan, but it's not clear how, since we can't really trust anything he says.

There's probably more, but I don't feel like digging.


Here is what I'd guess about magic:
Youthening your appearance is fairly simple through a variety of methods, but it doesn't actually do anything to stop your aging and when the magic snaps it snaps hard, generally leaving you worse off than if you hadn't used it in the first place. Actual life extension is much rarer, but there are a variety of forms of it too. But generally speaking they will be difficult or dangerous, and there's always a cost.