As Cadia Falls and the Thirteenth Black Crusade begin with the opening of the Great Rift and the sundering of the Imperium into two parts: Imperium Sanctus, which still has the light of the Astronomican, and Imperium Nihilus, which has been cut from its guiding light, the forces of Chaos begin to attack like never before. Worlds that have rarely been threatened burn under heretical invasion. One of these worlds is Kharon IV.
Kharon IV is a thriving Imperial industrial world located on the fringes of the Segmentum Obscurus, known for its massive manufactorums and hive cities. The planet is critical for the production of munitions and supplies for the Astra Militarum. The Death Guard, under the command of Typhus the Traveler, has launched an invasion to corrupt Kharon IV into a plague-ridden wasteland, cutting off vital resources to the Imperium and spreading the influence of Nurgle.
The invasion begins with a massive Warp breach in the system, heralded by the arrival of Typhus' flagship, Terminus Est, and a fleet of corrupted vessels. The skies over Kharon IV darken as clouds of spores and filth rain down, spreading sickness among the population. Plagueburst Crawlers and Blight Drones are deployed to key manufactorums and communication hubs. The Death Guard forces target power stations and orbital defense platforms, crippling the planet's ability to defend itself. The Death Guard lands in force around Hive Tertius, a major city that serves as a central hub for the planet's manufacturing industry. Massive, corroded drop pods slam into the city's outskirts, spilling forth squads of Plague Marines, Poxwalkers, and Nurgle Daemons.
The Planetary Defense Force (PDF) and elements of the Astra Militarum muster a desperate defense, setting up kill zones and barricades. However, they are quickly overwhelmed as the Death Guard's relentless advance is accompanied by the spread of debilitating plagues that weaken the defenders. The Death Guard lay siege to the hive city, bombarding its walls with corrupted artillery. Inside, the population succumbs to horrific diseases—those who fall rise again as Poxwalkers, shambling towards their former comrades in a gruesome parody of life.
Typhus leads a direct assault on the Hive's primary manufactorum, aiming to corrupt its Mechanicum reactors and unleash a tide of toxic waste that will spread across the planet. The defenders launch a desperate counterattack, but they are no match for Typhus and his Terminus cohorts. The remaining loyalist forces retreat to the inner sanctum of Hive Tertius, where the planetary governor and a handful of elite units prepare for a final stand. The air is thick with flies, and the walls weep with filth as the Death Guard close in.
It is around this time that things get worse for both sides as a new Warp breach opens, and the massive fleet of the WAAAGH Eternal arrives to join the fun. Led by the Galaxy Burna, the massive Ork fleet charges toward Kharon IV with only one goal in mind: to give everyone and everything on it a good kickin'. True to the insurmountable fortitude of the Death Guard and thinking this is just an unusually large but standardly stupid Ork fleet, the Plague Fleet, with the Terminus Est at its head, powers out to meet them. They quickly learn how wrong they are.
The Death Guard Fleet splits to surround and trap the Fleet Eternal, expecting them to charge right into the trap like any normal Ork fleet would. The ship commanders and daemon machine spirits are confused and surprised when the Ork fleet splits apart to meet them, sending three ships to meet every one of the Death Guards. In the center of this, the Terminus Est and the Galaxy Burna charge directly for one another. The massive Luna-built Daemonship, bloated from over ten millennia of being steeped in the power of Nurgle for one of the few times in its existence, finds itself outsized by an enemy vessel as it stares into the gaping maw of the Galaxy Burna. The gaping maw begins to glow with green energy.
The Terminus Est is mainly controlled by its daemon machine spirit when Typhus is not on board. This daemon is one of the most blessed of the Grandfather and master of void warfare. Known for being able to absorb levels of punishment that will kill another ship ten times over, the Terminus Est rarely ever backs down from trading blows. So, the fleet is shocked once again when it cuts speed and starts to turn instead. While it does this, the Nurgle Hives that cover its surface in place of guns start to erupt violently and hurl a mixture of corroded debris, ammunition, and filth out into space at the Galaxy Burna. While the bloated daemon flies known as the Miasma of Pestilence thicken in an attempt to shield the daemonship with their bodies. It does this because it understands the severity of its mistake as it senses the unbelievable build of Warp energy in the maw. It is far, far too late.
The daemon machine spirit screams out for the aid of the Grandfather as the Maw gains full charge. Its screams are drowned out by roaring Ork laughter as the Maw fires its reality, tearing beam of Warp energy. The lance burns through the cloud of Warp flies, hitting the center of the legendary Daemonship. For a second, nothing happened. Then the Terminus Est is torn to pieces as a second smaller green Warp Rift is torn into reality. This one acts like a black hole, dragging several of the Death Guard ships closest to their flagship into it. It closes within seconds, leaving those that were halfway in sheered in half. The wound left reality bleeding in its wake, but the damage to the Death Guard was far worse as the psychic backlash from the destruction of their ancient ship hit those on the ships and the planet alike like a sledgehammer to their tainted souls. None suffer more than Typhus, who falls to his knees before a slain Baneblade and howls in more agony and grief than he has ever felt in life.
The Orks care nothing for the momentous occasion beyond cheering at the sheer destruction unleashed by their Boss. Nor do they give the Death Guard a chance to grieve. Warp Portals start to open on every remaining Death Guard ship as thousands of Orks belonging to Red's Space Mobz storm them wearing their new boarding armor, which is etched with anti-Warp runes to protect the Warp plagues that fill every vessel. Even though Ork's biology makes them pretty immune anyway, she leaves nothing to chance. The same has been done to the armor of the millions who port down to the planet at Killkrumpa's side.
Those who witness the Biggest Boss step from the portal this time witness the true avator of their twin godz. WAAAGH and Warp power bleed off him like green smoke. The fingers on all four of his massive hands habe been transformed into massive power claws that crackle with green Warp Lightning. Warp shootas have grown from the back of each clawed hand. He has grown a long Necrodermis tail that ends in a bladed fork tail. Two massive Necrodermis wings habe formed on his back.
Green flames shoot from his mouth as he leans back and roars, "WAAAAAAAAAAGH!!!"
His Boyz echoes the roar, and the citizens and the world of Kharon IV shake with terror.