

Immortal/Undead
All immortal creatures are undead, so they are usually lumped
into the same category. Basically, the body dies and the soul
continues living. The manner in which it continues depends on
the individual's level of life force.
If a person with a low/average life force suffers a mortal
death, the soul dies too. The only way around this is if
someone uses their own life force to keep the soul from
dying at the moment that the mortal death occurs.
If a person with an above average life force suffers a mortal
death, their soul usually dies too. But if the person has prior
knowledge of the after life and the undead, or is deeply
spiritual, they may become immortal.
If a person has a high life force, their soul may survive and
become immortal. This is still unlikely with out a prior
knowledge of the after life, though. Almost all the undead fall
into the first and second options, and a few special ones fall
into the third.
Now that the soul has survived death, it will become a ghost,
angel, demon, or beast. All immortal creatures have
distinguishing characteristics, but in common they have: the
ability to fly, rapid tissue/cell regeneration, no heart beat,
no body heat, hightened senses and animalistic tendencies.
Also, immortals are not actually immortal. They can still be
killed or die on their own. They cannot die of old age, but
generally die between the ages of 200 and 500. In death, you
gain an acceptance of death and most just allow themselves
to die.