The prophesied plan was going well Cegorach thinks. His Harlequin forces were nudging the strands of fate into the right directions, diverting important battles to where and when they needed to be and ending enemies before they could get dangerous.
But his plan to awaken Ynnead before Rhana Dandra should not be the only plan going even if it was the one with the highest payoff. He needed some new plots to plot and plans to plan else he gets bored. Boredom was the second biggest threat besides Chaos in his opinion.
So Cegorach drifted through the Webways of the old ones looking for something to do that might help the fight. He drifted towards human worlds this time, his Harlequin forces were devoted and the Eldar his chosen people but they could be so stuffy and boring sometimes so humans seemed more fun right now.
He found a Solar system with a few inhabited worlds with some actual fun going on on them! Parties and festivals and art and all manner of performances flourished in this system unlike so many of the worlds in the Imperium of man. He looked back into its past and found it was cut off from regular warp travel and so had never joined up with the Imperium after the age of strife, this was promising.
He hovered over all the departing souls entering the immaterium from realspace on the planet and checked them to see if he could find anyone suited to his purposes. Oh this one over there, just died from a mountaineering accident. Wasted potential on this planet no real big issues to tackle there and this soul was meant to take on big problems and solve them.
He snatched her soul from near her corpse and away from the waiting warp horrors that would eventually find and devour her soul and pulled her into an illusory space in his soul so they could talk.
She wakes up naked on a pitch black floor in a pitch black void with a 20 foot tall too thin masculine figure with too long limbs wearing a blank mask and a jester's outfit just a few metres away staring down at her. One would imagine this would be a shock to this newly departed soul.