Accursed forevermore is Yamil Zacra, star of perdition, who sitteth apart and weaveth the web of his rays like a spider spinning in a garden. Even as far as the light of Yamil Zacra falleth among the worlds, so goeth forth the bane and the bale thereof. And the seed of Yamil Zacra, like a fiery tare, is sown in planets that know him only as the least of the stars .... -Fragment of a Hyperborean tablet.
This story grabbed a hold of my imagination and never really let go. I could never find that book again in the library, despite my best efforts at looking. But a couple of years ago I discovered the story online at Eldritch Dark, a CAS devoted website.
This dredged up another half-forgotten memory of Nemesis, the hypothetical red- or brown-dwarf star that obits our sun. The theory is that Nemesis causes extinction events about 26 million years or so. The two certainly could be one and the same in a near-apocalyptic game.
Yamil Zacra: The Infernal Star
Somewhere between the stars Polaris and the acknowledged evil star Agol, lies a star nearly invisible to the naked eye; but a star whose ill light shines on Earth still.
The star, Yamil Zacra and it's darker, smaller companion Yuzh, though were once worshipped as evil gods by the Hyboreans and the twisted sorcerers of Mu. Astrologers say that it's foul light was visible when Atlantis sank and the contents moved. In the far future, when many stars have burned out their fuel, they will again be honored by the fell Necromancers of the last continent of Zothique when the Earth is dying.
The ancient Hyboreans believed that this evil star bore the seeds in which all foul magics have grown. That the greatest and most terrible of witches, necromancers and foul wizards were born under it's light.
These magics may be realized when certain amulets of black extraterrestrial metal are grafted into the skin, most often the chest, of those willing. These amulets fell to Earth in ancient times were from the solitary planetary body of Yamil Zacra, a twisted world know as Pnidleethon.
Once in the possession of one of these amulets the dreams of Pnidleethon and Yamil Zacra begin including the means to travel to this chthonic world. When the amulet is finally embedded into the prospective student's chest he forfeits forever his soul and Earthly shell in favor for a form to travel the distances across cold space to the immense world of Pnidleethon.
The scene of these latter dreams was not the Earth, but an immense planet revolving around the sun Yamil Zacra and its dark companion, Yuzh. The name of the world was Pnidleethon. It was a place of exuberant evil life, and its very poles were tropically fertile; and the lowliest of its people was more learned in wizardry, and mightier in necromancy, than the greatest of terrene sorcerers. How he had arrived there, the dreamer did not know, for he was faint and blinded with the glory of Yamil Zacra, burning in mid-heaven with insupportable whiteness beside the blackly flaming orb of Yuzh. He knew, however, that in Pnidleethon he was no longer the master of evil he had been on Earth, but was an humble neophyte who sought admission to a dark hierarchy. As a proof of his fitness, he was to undergo tremendous ordeals, and tests of unimaginable fire and night.Yamil Zacra in WitchCraft/Buffy/Ghosts of Albion
It is rumored that the possession of such an amulet will increase one's magical energies ten-fold. In game terms increase the character's Sorcery/Magic by +10 or increase their Essence 10 times. While this seems to be great remember at this time there are only two amulets left in the world and the user forfeits their own soul for this power. The soul is not given to some demon or even otherworldly god, but it is consumed whole.
In the Armageddon game I would have Yamil Zacra appear in the nigh sky, a brownish-red blotch on the night sky. It casts no light, save for those already under Leviathan's influence, but everyone can feel it's heat.
Yamil Zacra in All Tomorrow's Zombies In the present day it is difficult to travel to Yamil Zacra and Pnidleethon other than by eldritch or sorcererous means. But in the future worlds of ATZ such an expedition to a planet that is seemingly dead is different sort of tale.
Option 1: The planet is dead. The crew lands on a planet where there had once been a great, if evil, civilization. Yet something is still out there in the dark picking off the cast one by one. It's Cthulhu meets Aliens, or "Journey To The Seventh Planet" with less suck.
Option 2: The planet is alive. Here the civilization of seemingly advanced humans still thrives. But the cast is trapped. Think of the song Hotel California and apply it to the entire planet. Or, Planet Ravenloft.
Escaping in either case is the goal, the means in each option differ. In Option 1 it is just get back to the ship before you all die. In Option 2 it is figure out how to get back to the ship and get out.
Yamil Zacra in D&D4
Obviously one of the dread and fell stars that grant warlocks their power.
More Revelations of Melech
Yamil Zacra: When civilizations fall, it is the light of Yamil Zacra that falls on them. It is a dark red star barely seen by mortals, those that can see it know it is a portent of doom.
Level 23 Encounter Spell
The Doom of Yamil Zacra Warlock Attack 23
For brief, horrible moment the light of Yamil Zacra shine on your enemy, revealing the doom that must come to all.
Encounter ✦ Arcane, Radiant, Fear, Implement
Standard Action Ranged 10
Target: One creature
Attack: Constitution vs. Fortitude
Hit: 4d8 + Constitution modifier Radiant damage, and the target grants combat advantage to all your allies until the end of your next turn.
Star Pact: If this attack hits, the target takes a penalty to Will equal to your Intelligence modifier until the end of your next turn.
Infernal Pact: If this attack hits, target also takes Fire damage equal to your Intelligence modifier.