Immortality

The power in which one is unable to die. In many novels or other fictional stores, this power is coveted by the primary antagonist, in which the main character must stop him from obtaining it. Some immortals also have Invulnerability, making them true Immortals. An immotral can live for eternity and therefore can never age and grow old, meaning staying young forever.

In the anime "Mermaid's Forest" the immortals such as Yuta, Mana and Masato can quickly heal from any physical wound-no matter how great- in mere seconds. If an immortal is killed, however, he or she will return to life fully healed and unharmed as if reborn within twelve hours.The only way for an immortal who has eaten mermaid flesh to truly die and not return to life is by beheading them. Immortals can live for hundreds or thousands of years, never aging. Examples are Masato and Yuta. Immortals obtain the exact physical youthful appearance of the time they first ate mermaid flesh. For example if one eats mermaid flesh at the age of fifteen he or she will remain the exact physical youthfuf appearance of a fifteen-year-old teenager for centuries or even millennia.

Capability
The user can never die. Although the user still experiences pain and injuries, mortal wounds result in the user becoming unconscious until injuries are tended upon, but their body will never rot, age or grow old. The possessor will stay young forever.

Associations

 * Possibly accompanied with accelerated healing factor, longevity and Self Healing.

Limits

 * Submitting into effects from a black hole are highly unknown.
 * Can't overcome the End of Time, unless the form of immortality is and infinite absolute.
 * Some, like the Highlighter, can only be killed in a certain matter.
 * Some immortals, may die via decapitation or destruction of their molecules.
 * An effect of being immortal is the user may become mad, from the effects of time and boredom.

Universal differences
In some ways Immortality just means that one could never die of old age or sickness. The norse gods for example ate golden apples that prevented them from aging, though they could still die (Ragnorok caused the deaths of Odin, Thor, Balder, and several other gods. in mythology.

Variations
Some may only possess the power of:
 * Revivification/Rejuvination: The power in which one regains life and consciousness whenever they die.
 * Quick Reincarnation: The power to be immediately reincarnated following "death"; can result in gaining powers in relation to how the user previously died.
 * Invincibility: Cannot be harmed in any way or form, therefore death is omitted.
 * Death: No body to destroy. The soul, one that is not of a physical being, does not inherit physical characteristics, such as concepts of destruction, therefore cannot be destroyed. Most common form of immortality.
 * Resurrection Death is omitted. Injuries may be inflicted, but complete annihilation is impossible.
 * Chronolock: Can only someone to live for an untold amount of time, by living outside of it.

Known Users

 * Gods (Christianity/Judaism/Islam)
 * Goddesses
 * Scarlet Witch
 * Sun Wukong (Journey to the West)
 * Jason Vorhees (Friday the 13th)
 * Adam Monroe/Takezo Kensei (Heroes)
 * Thanos (Marvel Comics)
 * Mister Immortal (Marvel Comics)
 * Deadpool (Marvel Comics, via curse)
 * Doomsday (DC Comics, via Reactive Adaptation)
 * Hidan (Naruto Shippuden)
 * Primus (Transformers) Has an Indestructible Spark.
 * Unicron (Transformers) Same as his Brother.
 * Starscream (G1 Transformers)
 * Rampage (Transformers: Beast Wars) Same as Primus and Unicron.
 * Captain Jack Harkness (Doctor Who, Torchwood) Dies and then is revived a few minutes later.
 * Vandal Savage (DC Comics)
 * Immortal Man (DC Comics)
 * Resurrection Man (DC Comics) (Vandal Savage is the arch-enemy of both)
 * Alucard (Hellsing)
 * Van Hohenheim (Fullmetal Alchemist) (Loses his immortality after using much of his power and dies peacefully)
 * Father (Fullmetal Alchemist)
 * Aizen (Bleach) (Due to Breakdown Sphere/Hogyoku)
 * Nathan Young (Misfits) (Unclear if he is immune to aging)
 * Garlic Jr. (Dragon Ball Z) wished for immortality with dragon balls
 * Professer Ivo (DC comics via serum)
 * Kenny McGormick AKA Mysterion (from South Park)
 * Thor (Marvel and Norse mythology)
 * Loki (Marvel and Norse mythology)
 * Enchantress (Marvel and Norse mythology)
 * Zeus (Percy Jackson)
 * Atlas (Percy Jackson)
 * Chiron (Percy Jackson)
 * Artemis (Percy Jackson)
 * Hera (Percy Jackson)
 * Posiedon (Percy Jackson)
 * Gaea (Heroes of Olympus)
 * Voldemort (Harry Potter, formely by Horcrux's)250px-Thor_Odinson_(Earth-616).jpg
 * Bryce (NeverDead - videogame)
 * Connor MacLeod (Highlander)
 * Duncan MacLeod (Highlander)
 * Caleb Mathias (Mutant X, via resurrection)
 * Pierre Bauvais (The X-Files, resurrection via voodoo magic)
 * All Immortals (El Goonish Shive)
 * Marceline the Vampire Queen (Adventure Time)
 * Professor Paradox (Ben 10 Alien Force/Ben 10: Ultimate Alien)
 * Yuta (Mermaid Forest, from eating mermaid flesh and was granted immortality, both eternal life and youth)
 * Mana (Mermaid Forest; from eating mermaid flesh and was granted immortality, both eternal life and youth)
 * Masato (Mermaid Forest) (from eating mermaid flesh and was granted immortality, both eternal life and youth and has been alive for eight hundred years)
 * Mermaids
 * Mermen
 * Beloved (The Unicorn Chronicles-from the tip of the unicorn, Whiteling's horn embedded in her heart)
 * The Chrion (The Unicorn Chrinicles-from having his vital essence placed in a jeweled golden egg; though his aging was slowed greatly)
 * The Lich (Adventure Time)
 * Shadow The Hedgehog (Sonic The Hedgehog)
 * Golden Boy from the Wild Cards series