The Tome of Decay (2014), p21 — Nurgle and the Long War

"The Imperium drew its last breath long ago. We are merely awaiting its death rattle, and then entropy shall claim its long-awaited victory. We are patient. We have waited ten thousand years. We will wait ten thousand more, if necessary. But I do not think it will be."
— Lethrax the Blighted Hand

For a Plague Marine or other Chaos Space Marine in the service of Nurgle, the timeless nature of existence within the Warp is a gift beyond measure. Many of the lessons and experiences that lesser mortals are unable to fully appreciate, let alone comprehend in any significant way, are theirs to explore. It gives these warriors an eternity to ponder the grandeur of their master's plan for ultimate corruption. The many diseases they have within them are given time to percolate and properly evolve into ever more deadly forms. Perhaps best of all, it may allow them to live long enough to see rot claim the body and soul of the False Emperor as he withers away to nothing on his Golden Throne. While the unfocussed followers of Tzeentch waste time in futile attempts to find new ways to breach the Imperial Palace, the patient Chaos Space Marines of Nurgle know that inevitability is their ally. They have but to wait for the great victory, for nothing is eternal - not even the Emperor and his domain. For these enlightened and blighted warriors, the Long War does not seem as long as it does to others.

This is not to say they do not harbour the same righteous hatred for their former brothers that all Legions share. While they know they could simply wait for victory to come to them, they choose to follow the example of Nurgle himself and take a more active role in the downfall and renewal of the galaxy. Eternity offers them many ways to revel in the joy of living and to gain satisfaction from the death they can bring to their enemies. There are a thousand worlds ripe for virus bombing. Billions of souls wait to be tormented by plagues of the spirit. The flesh and bones of entire Space Marine chapters are there to be harvested and used as experimental subjects for Nurgle's constantly mutating catalogue of diseases. It is the duty and privilege of the veterans of the Long War to see to it that no opportunity to further the great cycle through acts of vengeance upon the Emperor's lapdogs passes by.

The betrayals committed against the Legions in the days of Horus' war against the bonds of undeserved servitude are fresh in the minds of all who fought in those days. Let Khorne's brainless savages mutilate the warriors of the Adeptus Astartes. Such violence has a place. If the appetites of Slaanesh's brain-addled devotees get lost in the pleasures of the kill, so be it. Even the erratic, misguided actions of Tzeentch's minions can, at times, create diversions that force the enemies of the Ruinous Powers to weaken. None of this can compare to the all-encompassing totality of the Plaguelord's grand design. As empires crumble, stars collapse upon themselves and each and every pathetic Space Marine chapter fades from memory, Grandfather Nurgle and his chosen servants will have the last laugh. The galaxy will die, and from its death throes a new existence shall come into being, with Nurgle ruling as lord over it all. Not a single one of the Emperor's loyal, wretched offspring shall persist to sully it.