Ancient Ones

Race Beyond the Wanderers of the Night (and following lines) They lived before any mortal races were born. They possibly were "guardians" of the Prime Material plane, back when there was no phlogiston, only utter blackness in there. Still, there are "wanderers of the night" – so the first stars were already born, maybe even with worlds and moons around; but no phlogiston, and no mortal life did exist.

Current Dynasty of HeavenA very Athar-like view, of course. The current dynasty are the current powers, but they're just usurpers, no real gods (though they might not even be aware of it... after all, some of them are good and honest, and wouldn't say they're gods if they didn't believe it themselves).

For We Contain the Divine Essence*Something* happened that made the Ancient Ones decide to retreat from this multiverse. Maybe the over-powerful Ancient Ones of the various concepts (Good vs. Evil, Law vs. Chaos) were about to clash with each other so hard that it threatened the very multiverse. They all decided to retreat, but leave "someone" behind to fight for their ideals. The baernaloths created the yugoloths (one of them created the gehreleths). The other evil Ancient Ones created the Elder Baatorian and the Elder Tanar’ri. The neutral Ancient Ones created the Rilmani.

The good ones... tried something riskful. One of them gave his own life to create something utterly new: Mortals. Not bound to any concept, these new beings were meant to find their very own way to what was right and wrong. After all, the Ancient Good Ones themselves became a threat for the multiverse in the war versus Evil.

Maybe these mortals would find a way to bring goodness to the multiverse without threatening it. First, they were left alone, as the other races didn't even know about the mortals. But as soon as they were found, the Ancient Ones of the other races decided to also create mortal races. Among them were the illithids, the race for Baator, and many others.

So did the Prime get populated? The phlogiston? It's the blood of the first Ancient One to give his life for mortals. Nourished by... Fire, Water and Wind for the Elemental planes. Maybe, in the very beginning, Earth didn't exist...? Wrath, Rage and Tears: Symbols for the Outer Planes; they were embodiments of the feelings that lead to wrath, rage and tears. The reasons behind these emotions defined Goodness, Neutrality and Evil.

I think the Old Ones in the Plane of Ice could be the Good Ancient Ones who have hidden there until the time they're needed again (probably for The Final War, Ragnarok, the Apocalypse, or however you wanna call it).

We Blossom at the Root of the Tree of KnowledgeYggdrasil could be meant. If so, the Crystal Sphere would be the Root of Yggdrasil, the tree that grows and is nourished from the blood of the Ancient One (from the phlogiston). It is the tree who keeps the Ancient One's knowledge and personality, and only as long as Yggdrasil lives, can the Ancient One come back (or maybe, can the mortal races exist). The Astral Conduits could actually be Roots of Yggdrasil, or rather the "veins" inside the roots.

We Wait and We RememberSome do. Very few, actually. But still, some mortals are aware of their divine origins, and they live a life for goodness, a passionate life striving for true divinity.

For the Blood of Man is the Blood of Vengeance: In The Final War, everyone will remember his origins, and Good, Neutrality and Evil will clash until one side wins. Good will seek vengeance for all the wrongdoing of the other sides, and for attempting to steal their divinity (i.e. letting them forget it).

Further IdeasThis background explains why fiends are so eager to get mortal souls in their clutches. Especially the 'loths and the baatezu (at least their high-ups, who then coordinate their inferiors actions) might still be aware of the divinity of mortals. That's why they want them enslaved or destroyed. And in the end, they strive for the Apocalypse, for the destruction of the multiverse, so to be able to build their own new multiverse upon the ruins, one without goodness inside it.

The Neutral Ones are probably striving to keep existence as it is. That's why they support evil one time and good the other, never wanting one side to win the upper hand, for that will eventually lead to The End.

And it's why the Good Ones are so eager for everyone to rise to perfection (the Ways of Goodness on Mt. Celestia, the absolute Passions of Arborea [which probably the Neutral Ones successfully had interfered by more neutral powers, e.g. the Greek Gods], etc.). In the Seventh Heaven of Mt. Celestia, the Ancient One who killed himself (or rather, a last remnant of his mind) might be "available" for advice. And when the final day comes near, the warnings of those beings in The Seventh Heaven will make him awake his brothers and sisters in the Plane of Ice.

Adventure IdeasAfter all this talk about "the meaning of it all" (this surely isn't the first post for this), I think I'll actually do a campaign one day which, after an extremely long time, will end with Ragnarok. But for ideas for sooner use, one of those rare characters who are aware of their divinity could meet the PCs. Especially if they're good, but not really passionate fighters for Goodness. He might struggle to have them understand how important their passion and trust is. They probably will not understand all he says (he himself might know only little), but nevertheless he might be able to turn them to Warriors of Goodness.

Or, the PCs might find a way from Yggdrasil to an Astral Conduit. When in the Astral, someone interferes with their travel, and they end up in the Astral. There, they somehow realize that a couple of other conduits are nearby, and that they all lead to Yggdrasil in the end, even if "meeting" the Outer Planes first. Any PC interested in uncovering darks would probably be very passionate in such an adventure, even if there's no "arch-enemy" to defeat.

False PromisesThe PCs come into a world where one of the mortals (a character who's aware of his divinity) managed to convince people that the powers aren't real gods, and try to drive them out for their unjust rule. It's kind of a worldwide war of mortals vs. powers.

If Athar, this might be enough for a long campaign. If Godsmen, it might be even more interesting. Their factol knows the leader of the mortals has the spark of divinity in him, but he wants him to become a power himself (as he's convinced that's the "right and natural way"). Of course, the leader of the mortals tries to KILL the powers, and will not be very happy about someone trying to convince him to *join* the powers.

ReincarnationEven more extreme (stolen from Virgin Steele) a character was slain by the powers for seven times by now. In his seventh life, he suddenly remembers all that has happened, and the betrayal of the "gods". This might lead to the above idea, or another kind of vengeance of the mortal vs. the gods.

AmaranthThis is the flower that grows at the Root of the Tree of Knowledge. It could be tied to Spelljammer; a spelljamming captain who's making maps could notice that many Crystal spheres on his map, if seen together, actually look like a gargantuan flower.

The PCs might be on their way to find that captain, and find out the rumours about Amaranth (they might not even know what it's about). Or, Amaranth could actually be a "small" flower, and the PCs might find a clue to it (or even find the flower itself... should be the most disturbing & enlightening event the PCs have experienced thus far).