IF I were going to run an RPG set in the Warhammer 40k Universe (and I’m *not*):
At the very edge of the Imperium, a human has been born with the power to fuel her own Astronomican. At an early age she was found and protected by a group of Eldar who believe her to be Ynnead, the new Eldar God of the Dead who was thought to be unable to come into existence until every last Eldar died eons from now.
As she matured, “Ynnead” developed the innate ability to nullify psyker powers, an amazing raw talent that demanded training the Eldar could not provide. To aid her they found Senseis–descendants of the Emperor of Mankind who are psychic nulls–and trusted them with the secret of her existence. The Sensei trained “Ynnead,” and word of her existence reached the Thorian faction of the Imperial Inquisition, who came to believe she was the Star Child, the Emperor of Mankind reborn, and that her birth is proof that the mummified remains of the Emperor within the Golden Throne had, in fact, died.
The Thorians named her Malcadora, and decided her existence meant all the rest of the Imperium has fallen into heresy. The Thorian Inquisitors moved to claim as many Imperial resources as possible to support Malcadora/Ynnead, convincing a few Imperial Legions, Sisters of Battle, Deathwatch Space Marines, and members of the Ecclesiarchy to join their cause.
A New Imperium is planned, but is nearly destroyed before it can begin by the arrival of a Tyrannid splinter-hive. The Eldar and Thorians supporting Malcadora/Ynnead fight bravely, but are impossibly outnumbered. The Star Child God uses her powers to send out a psychic command for others to aid her… and she is answered by a sept of Tau (who claim supporting her is a crucial part of the Greater Good), and a Necron Dynasty, who acknowledge her as a reborn Necrontyr and an instrument of their revenge on the Old Ones and C’tan. Her command of a dynasty of Necron convince more Eldar that she is their new God of Death, and her support among them grows.
The brunt of the splinter-hive attack is defeated, narrowly, but Tyrannid and gene-stealers continute to be a threat to the rising organization serving Malcadora/Ynnead.
As the campaign begins, the so-called New Imperium is a tiny, fragile thing with barely a handful of worlds and smattering of massive Craft Ships, a single Necron Dynasty, a rag-tag Imperium presence, and a fleet of Tau allies to support it. On her Adamant Throne, built to aid in her slowly growing Astronomican, Malcadora/Ynnead strives to save all the souls she can, fend off armies of the Tyrannids and a growing Chaos interest in her and her allies, all while contending with advisers and allies who have fought one another for tens of thousands of years. She demands respect, but she demands it not just for herself, but for all life.
If the New Imperium is to survive, it must have agents. Drawn from many races and traditions, from Imperial forces to Rogue Traders to Necron Lords to Eldar, these agents must work together to find new allies, gather more resources, fend off the forces of the Tyrannids and Chaos, and prevent the still-hateful-and-fearful majority of the old empires of Man, Eldar, and Necron from slaying Malcadora/Ynnead as a heretic and potential new Chaos God.
You are one such agent. And you will work with creatures from many different races and backgrounds because Malcadora/Ynnead demands it. And because she may be able to save life and freedom within the Galaxy.
For in the grim darkness of the far future, now there is hope.