Greek Gods

A god is an immortal being, often living on Mount Olympus. There are twelve major gods and many minor ones.

History
The first six gods and by far the most powerful ones were Poseidon, Hades, Demeter, Hestia, Hera, and Zeus, the sons and daughters of Kronos and Rhea. Fearing his children would overthrow him in much the same way he had done his father, Kronos devoured his first two sons and his three daughters after they where born. He would have devoured Zeus as well but Rhea, unable to bear the pain of losing another child and seeing her husband now for what he was, plotted to save her son from the fate of his siblings. Entering into an alliance with Gaia, Rhea was able to smuggle her son away to safety and gave her husband a rock instead to devour. Kronos devoured the rock without question out of arrogance as he had already devoured the other children and he didn't expect his wife to resist him.

After years in hiding, Zeus was finally old enough and strong enough to overthrow his father, and returned to his father's palace to free his siblings who, being immortals, remained alive and undigested within their father all this time. There are many different accounts of how Zeus freed his family but the most famous was when he smuggled a potion in to his father's meal, forcing him to vomit up the children up, and lead the revolt against him.

The war lasted ten years with neither side gaining any true or clear advantage over the other, until finally the gods played a gambit that to some would have been considered suicide. Traveling to the Underworld they released the Cyclops and the Hundred-Handed Ones who had been imprisoned by Kronos; so long has they would aid the gods in battle. They agreed. The Cyclops forged the Big Three their symbols of power; The Master bolt, The Trident and the Helm of Darkness, while the shear strength of the Hundred-handed ones proved to be a great advantage against the Titan army.

The final blow came when the Big Three took the fight to their Father. The plan was simple and effective; Hades would use the Helm of Darkness to enter the Titan armory and destroy their weapon which would then allow Poseidon to use the Trident to attack the defenseless soldiers leaving Kronos open to attack by Zeus and the Master bolt. The plan was a success and the final blow was delivered when Zeus using his Father's own scythe; cut Kronos in to a thousand pieces and dropped them in Tartarus where he would (hopefully) never rise again. This marked the end of the Titan age and the start of the age of the Olympians.

The Olympians have been challenged many times, but they have always come off on top, with the help of their children, the demigods.

Appearence
All gods have a true form that is too intense for lesser entities to observe, and if any lesser entity were to look upon a god's true form it would destroy them. A god can show some of their true form to a demigod through their eyes, which Percy Jackson has experienced many times. Gods can naturally change between their normal shape and an assumed shape at will, but if they become angry enough they will uncontrollably revert to their true form unless they regain control of their emotions. This happened with Hades in The Last Olympian when he found Maria's dead body. The grief and rage at the sight of her dead body almost caused him to revert to his true shape but he was able to regain control of himself so that he didnt vaporize his own children with the force that would have been released with his transformation.

Powers
Each god has specific powers based on what they represent, but they all share certain powers and even powers specific to their individual domains can overlap.

Powers shared by all tend to include immortal, shapeshifting, and a broad range of magical abilities.

Gods can alter their shape to whatever they want including gender, age, species and even more exotic things like fire. Most gods typically have a common human form they use when interacting with others that can be viewed as their "normal" form.

Gods possess a broad range of magical abilities including levitation, teleportation, and conjuring food and walls of fire or doing just about anything they want. The limits of a gods power in this regard is unknown nor is it known to what extent they can cross into the domain of another. Both Zeus and Poseidon have displayed the power to conjure storms and in ancient myths Hera demonstrated similar powers, but it is uknonw if Ares could conjure a storm himself or if there are limits on what they are allowed to do in this regard.

Gods can appear multiply places at once if something about their domain is being invoked. Dionysious was able to mainfest at a party despite his "true" self being buried under a mountain. It is unknown how many of these "copies" can be made at once, what powers they have or anything else about them.

Gods consume a heavenly food called nectar and ambrosia. It is unknown if they can maintain their powers or live without it.

Rules
Despite their vast powers gods are bound by certain rules. Some of these rules are laid down by Zeus and others are just in the nature of being a god. Only a few of these rules have been explored.

1. No god can directly steal the symbol of power of another. This applies to both the Titans and Olympians and is why Zeus knew a mortal had to have stolen his master bolt as mortals and demi-gods are excempt from this rule.

2. No god can by force inter the domain of another. It is unknown if this rule applies to all gods or is an edict of Zeus. It is known this is what prevented Zeus or Poseidon from going to the underworld themselves to check for the master bolt and that heroes are excempt from this rule. Further details on it are unknown.

3. Gods are limited to how much they can interfere in mortal affairs. This rule appears to be a decree of Zeus and not so much a rule about their nature. It is also depends on how much Zeus enforces it or knows about it as gods have been known to interfere when they were not supposed to with nothing happeng to them.