Eldrad Ulthran, possibly the most powerful psyker born of the dying Eldar race and of Craftworld Ulthwe, was lost, attempting to halt the destruction of Cadia by a Blackstone Fortress. He foresaw his fate in utter darkness, and marched to war regardless, and indeed the legendary Farseer was considered dead and lost to the Eldar, soul claimed by Slaanesh, She Who Thirsts, but some small hope remained in the hearts of other Eldar. While he was ordained with many spirit stones, many of which have long become dead and lifeless, some of these few remaining stones retain their spark of light, indicating that the soul of Eldrad may not yet be lost in full, trapped somewhere in the Realm of Chaos, seeking escape or rescue, though no living Eldar has had the ability to track down any lead on finding a way to confirm or deny such an incredible thing, although the hope alone is kept alive.
A gifted seer, thought to be just reaching the beginnings of his powers, died abruptly within the Craftworld of Ulthwe itself, but not without good reason. A powerful vision, that led to such a lethal end to his life, came upon him, and he fervently spoke of what he saw to those around him, of what brought credence to that faint hope of the ability to rescue Eldrad. He spoke, in his dying moments, of war and bloodshed, on planets distant and near, and of the eventual return of Eldrad, striding out amongst his peers. He uttered the word of one planet, Savaash, and finally perished, his spirit interred into the Infinity Circuit, while the information he had given, in his last moments of life, was shared and investigated. For indeed, the planet of Savaash was indeed a real place, occupied by the Monkeigh Imperial Guard, who referred to themselves as Catachans.
Ulthwe looked to its denizens, a call for volunteers for this mission, only taking 200 of the most talented Eldar from all paths that would come forward with masterful skill and good reason to the expedition. And the call was indeed answered, and 200 of the most potent and powerful Eldar of many paths came forward to seek out Savaash, and wherever the strands of Fate might lead them, for the sake of Eldrad, the most powerful of their kind, his kin amongst the Craftworld Ulthwe would go forth, with the flames of war and the honed minds of warriors, all to seek this means of reclaiming the soul of Eldrad from She who Thirsts, or from wherever he ended up after his loss during the 13th Black Crusade might have cast him to, all for the sake of finding the truth behind the visions of a lost Seer.
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So, in short, the players will be taking the parts of various Eldars, who walk along the varied Paths from the Craftworld Ulthwe to seek the way that was forseen by the now dead Seer to try and bring about the end events, the return or, at least, rescue of Eldrad from his current fate. Obviously, his actual location is unknown, but the search is starting on a Catachan held world of Savaash, and so off they will march in search of the next step forward. So, would anyone be interested in this at all?