Gods, Demigods, Elder Gods, and the Primordials

Primordials

The Primordials are the creators of the universe.  They also created all of the realms, except for the material realm and the various prison realms.  Each realm was created by a single primordial, who represents the aspect that their specific realm is comprised of.  Since it is unknown how many realms exist, it is also unknown how many Primordials there are.  In addition to the realm, they also created/parented the Elder Gods.  They are immortal so although they are not dead, most of the Primordials are no longer around, having merged with their favored realms.  Only Orongi the Destroyer, the Primordial of Destruction, remains.

Elder Gods

The Elder Gods created the material realm as well as the first lifeforms.  These lifeforms were primitive and allowed to develop naturally.  Of course, the Elder Gods would occasionally interfere, thus revealing themselves.  This allowed them to discover the power of worship.  They are the parents of the Gods.  The Elder Gods ruled the pantheon for untold millennia until Orongi the Destroyer decided to usher in the end times.  It took an alliance of all the Elder Gods, all the Gods, and the entire population of Malferno to defeat him and even that was not enough to kill him.  Instead, Orongi was banished to a specially designed prison realm, where he awaits the time when he will return.  Although the Elder Gods are immortal, Orongi is powerful enough to kill the unkillable and dozens, if not hundreds, of Elder Gods were destroyed during the battle.  Only a few remain and those that are gone have been largely forgotten by the world.  

Gods

The Gods are the children of the Elder Gods and are the ones currently overseeing existence.  Like the Primordials and Elder Gods, they are immortal and normally cannot die unless killed by an exceptionally powerful magic weapon specifically designed to do so or by a being such as Orongi the Destroyer.  After the battle with Orongi, the material realm was left devastated and many, but not all, of the previous lifeforms were extinct.  The Gods created new lifeforms to repopulate the world, including elves, humans, etc.  While they can be petty and selfish at times, they genuinely care for their charges in the world and want the best for them.  Although not all the Gods agree on what’s best.  Thousands of years ago, Kazluri, the God of Tyranny, tried to conquer the material realm and personally rule over it himself.  When the other gods thwarted this attempt, he lead a revolt to usurp the throne and become king of the gods.  This battle was brutal, but Kazluri was defeated and banished to a prison realm for his trouble.  Several other deities, both gods and elder gods, have also been sent to prison realms for some terrible offense.  Worship of these deities has been outlawed by the material realm’s temple system.

Demigods

Demigods are the children of a mortal and a god or elder god.  They appear like any other member of their respective species.  They are also still mortal.  They age and can die.  However, due to their divine heritage they have special powers that are unique to each demigod.  These powers vary wildly and are often different depending on exactly who the divine parent was.  Many demigods go on to become legendary figures.  Most have become heroes, but a few demigods have been the most vile villains in history.  If their deeds are great enough, it is possible for a demigod to ascend to godhood, although there is currently only one known case of this.