Immortal: the deathless beings of the realms

Immortality was the condition of the gods, the titans, and certain great creatures of the Greek and Norse worlds, who could not die by age or by disease. It was never the same as true invulnerability, for even the deathless could be brought down by sufficient power, whether the strength of another immortal or a weapon forged to kill gods. (God of War II; God of War III; God of War (2018))

The nature of immortality#

To be immortal was to be free from natural death. The gods, the titans, and some great creatures did not age once they had come into their immortality, took no harm from any human or supernatural disease, and could survive injuries that would easily destroy a mortal. (God of War II; God of War III)

Yet immortality granted safety only from natural death, never from death altogether. The deathless could still be slain, and the more powerful the immortal, the more difficult it proved. Zeus survived many stab wounds from the Blade of Olympus, the very weapon that killed Athena with a single stroke, while lesser undead soldiers fell by the dozen to almost any weapon at all. (God of War II; God of War III)

Slaying the deathless#

An immortal could be killed only by the power of another immortal, whether a fellow god or titan, or a demigod grown strong enough, or by weapons that held godly power. Among such weapons were the Blade of Olympus, the Gauntlet of Zeus, and the Blade of the Gods, and most notable of all was the power of Hope, which could undo even the mightiest of the immortal. (God of War; God of War II; God of War: Chains of Olympus; God of War III)

True deathlessness#

Beyond ordinary immortality lay a deeper, terrible state: true deathlessness, in which killing became outright impossible. This could be achieved only through the magic of the Vanir, a spell that rendered its subject beyond any harm. The cost of such absolute invulnerability was the loss of all sensation. The deathless one could no longer feel, taste, or smell; the warmth of food and fire and the touch of the world were nullified, leaving the spell's bearer feeling as though not truly alive, incapable of pain but equally of pleasure. (God of War (2018))

Freya laid this spell upon her son Baldur, fearful of a prophecy that he would die a needless death and so begin the long winter that would lead into Ragnarök. The only way to lift the curse was for the deathless one to come into contact with mistletoe. (God of War (2018))