Following a Great Incursion from the North upon the southern Kingdoms, the Servants of Chaos are severely reduced in number both as a result of the fighting and in their trek back to their homelands, as well as resettling among their territories; new boundaries are drawn and old ones are tested. Long ruling chieftains and jarls fall in their duties to their dark lords and their sons and daughters rise in their places, only to be challenged in their turn by those who think them unfit to wear their predecessors crowns. Some clans return hearty, others devastated, and more still annihilated outright, their ancestral lands up for grabs by those who remain. There are power vacuums everywhere and no few ambitious marauders eager to fill them.
But beyond that, the Chaos Lords themselves shift and change in reflection of their own needs and the needs of their fractious people. Particularly, that the massive cost of lives is accounted for so that the Dark Powers still get their due of prayer and worship and reavers spilling south in their wolfships to plunder and pillage and sacrifice in their names. Also, for the next incursion, as the Powers will not rest until the world is buried beneath an unshakable pall of darkness and ruin. Either task require bodies; bloodthirster souls weaned on hardship and cruel gods.
Slaanesh is preeminent during this time, often but not always ascendent right after a Chaos Incursion fails. As the power chiefly concerned with lust, fertility, and fecundity, perhaps that comes as no surprise. The Dark Prince of Excess becomes the God of Flesh, Prince of Flesh, and the Mother of Mystery as priorities switch from perfection, battle, and torture, to fruitfulness and multiplying upon the land. If the spawn of such children are birthed or sired by captured southerners, that is all the better to the Prince.
Nurgle, too, shifts from the Father of Decay and Maker of Plagues to Lord of Life and Master of Disease. He too is beseeched in this capacity to quicken the wombs of the barren and to stay his hand from those babes born into the world so that they might be healthy and live for however long fortune or fortitude determines; after all, all things rot and so the Plaguefather will have his due in time.
Perhaps the most surprising and stark transformation is that of Khorne, as followers of the Hound put aside his aspects of war and death and bring forth a more metaphorical take on his domain of Blood. Rather than Bloodshed, it is bloodlines; Kharneth becomes Khorgar, the Virile One and God of Bloodlines. The Reaper of Skulls becomes the Sower of Sons. He is the blood of birth, the blood that signals the end of childhood and the ability to bring forth more warriors, the blood of a line long and a house ancient. By his will and his granted strength do old lines endure and new lines supplant the weak. Khorgarites do not suffer the misshapen or sickly to live among them; the former are abandoned at the edge of those tribes who worship tzeentch and the latter are surrendered to Nurglites. Only those who bear mutations evident of Khorne's touch are allowed to remain. Slaaneshi are most bemused by this aspect of the Blood God and many decry it for hypocrisy. Khorgarites answer pleasure is not their goal, but sowing more souls for the Hunter of Souls to reap.
Tzeentch's touch is perhaps the most subtle of the four, his power the most surreptitious after an Incursion fails. It is not in the people so much as the warp itself; everytime Chaos Fails, the Realm of Chaos creeps forward a few more meters, engulfing more of the land. More souls fall beneath Tzeentch's warping power. Tzeentch reaps a different tally in souls, shifting from Changer of the Ways to Father of Mutants. It takes nine months, the changer's number, in order for a human child to be born and during this time there is an influx of mutants. All mutations are considered blessings from the Gods, but those that are pleasing or at least useful are considered particularly fortuitous. It is said that the Changer merely mutates southerners for his own amusement, but after-incursion mutant births are champions in the making... Some go so far as to claim Tzeentch chooses the next Chaos Everchosen after the previous one falls, far before the other three gods even know whom it might be...
