Fading

Fading is the only way that gods can die. It is caused by diminishing of their realm or people not believing in their principles. Gods that are not well remembered or were never worshiped well can also fade, though exactly how this hasn't occurred to all the gods due to the end of their worship is unknown. Gods are able to resist fading to a certain extent, but it eventually overcomes them. It appears that belief in oneself can have psychological effects on fading. Demigod children of Hades can detect the fading of gods, or perhaps just when a dead or semi-dead one is near as seen in The Battle of the Labyrinth by Nico di Angelo.

Pan is only god that Percy sees fading during the entire series. Just before he faded, he passed his power on to Grover, giving the implication that fading gods can give a portion or all of their powers to a mortal just before they fade.

Known Faders

 * Medusa's Gorgon sisters
 * Helios and Selene
 * Cottus and Gyges
 * Pan
 * Uranus (Possibly)