During the creation of the Universe and the wars between the Gods, Beings were granted the ability to withstand the passage of time without perishing, while others were forced to live in a limited timeframe. For the first group, the term Immortality is established, the other group was defined as Mortals. While Mortals are defined by the fact that they die one day or through other means, Immortals can be classified in three groups.
While the term juvenile is not commonly kept, these kind of immortals are only in the strict form immortal that they cannot die from old age. Their physiology is normal, often keeping a visual appearance of an adult.
Most immortals have the power to defy the physical death. They are unable to die when their physical form is destroyed. Whenever they lose their body, they turn into the Ethereal and form their Ethereal Shape. In a short timeframe, they are unable to shift into the Earthen, but regain a new physical body after a while. This can be a fully reformed body, the old body healed or a form of rebirth.
True immortal barely exist. They cannot die through any means that are of Ethereal or Earthen origin. One of the only ways to destroy a true immortal is a simultaneous destruction of both the physical and ethereal body, or to successfully absorb the Soul of it. Should the physical shape be destroyed are they able to reform a body almost at once.