Godzilla
transfers some of his own life force to restore his son to life.Life transference technology comes into use mainly as a last resort for extreme medical cases. A last ditch attempt to restore a dying person's life... of course the side effects of each method have their other darker uses as well.
When one patient is on the verge of death, and another is already brain dead, then machinery can be used to transfer the minds and souls between the two bodies. The brain dead patient is now in the dying body, and the active mind is now within a perfectly functioning body.
This is usually done with a machine that transferee the minds without any major form of surgery, although a brain transplant would have the same effect, with more scarring.
Other uses for this technique are for espionage. Swapping the mind of one of your agent and putting it into a body of a rival faction gives you an instant deep cover agent into the enemy camp... or center of government if you were to transplant the mind of a president.
When cybernetic technolagy advances to the point that machine bodies can be created that are vastly superior to the evolved bodys, it is enevetalb for a group of people who will want to live in (or as) a cybernetic creation.
The disadvantages of doing this are mostly psychiological. It is easy for the transfered mind to develop a superiority complex, and in a sence becomes "souless."
Godzilla
transfers some of his own life force to restore his son to life.
This style of healing assumes that life cannot be created out of nothing, but may be transferred from one person to another. If the life donor happens to be immortal and is able to give multiple donations, then it is possible for someone to live forever. If the donor is not immortal, then the donation of life shortens their own.
This process can be done with a machine that connects both the life donor with the recipient, but is more often a "natural" ability made possible after genetic alterations are made to the donor.
Life force relocation can also be utilized as a form of punishment, purposely shortening someone's life.
When the death of the body is unavoidable, the essence of a person can be recorded or preserved within a matrix. The person preserved is aware and unable to interact with the world they once knew, and is rendered immortal... living for as long as their container allows.
People with strong wills can obtain a level of control over their containers... if they have been preserved within a computer or robot, they can learn to alter and control some of the functions of their host. If they are contained within some other medium, they may be able to influence any living beings that come into contact with their containers.