The battle in orbit had already transcended the scope of conventional naval gunfire exchanges, evolving into a terrifying clash of forbidden technology, characteristic of the Adeptus Mechanicus.
The fleets of Mars and Neksum, like two giants opening their long-sealed vaults, began to hurl terrifying relics from the Dark Age of Technology at each other.
For a time, the battle zone transformed into a bizarre experimental ground.
Invisible spatio-temporal distortion fields attempted to banish entire fleets into temporal discontinuities; malevolent logic viruses, like an electronic plague, spread wildly through the data networks of both sides' ships, causing system paralysis, weapon malfunctions, and even engine overload self-destruction; matter-disintegration rays silently swept across, erasing thick armor like sandcastles; localized gravity fields were instantly twisted to thousands of times their normal strength, crushing ships within their range like aluminum cans... In comparison, the rain of lances, macro-cannons, and torpedoes, their explosive flashes, became mere background starlight, decorating this insane battlefield, almost unnoticeable.
This was a feast of knowledge and destruction, where every second, precious, irreplaceable ancient technological artifacts were consumed, and every moment, ships carrying long histories were annihilated by attacks beyond comprehension.
Meanwhile, on the ground battlefield, the decisive force finally arrived.
Accompanied by heavy, earthquake-like footsteps and a sky-shattering roar of steam release and gear rotation, the titan battle group of the 'Iron Fists' Chapter stepped onto the Death World's soil.
These walking machines of the gods, like moving metallic mountains, were tall enough to dwarf the largest knight mecha.
The sole Warlord-class titan in the battle group fired first.
Its volcano cannon let out a deafening roar, and a searing beam of light instantly traversed dozens of kilometers, completely vaporizing a World Eaters company that was gathering in the distance, attempting to launch a new charge, along with the entire hilly area it occupied, leaving only a smoldering, vitrified crater.
Whirlwind missile launchers rose like a swarm of bees, covering a wider area with their deathly shrieks.
The three smaller Warhound-class titans, like loyal hounds, guarded the flanks of the Warlord-class, annihilating any scattered enemies daring to approach with their high-speed cannons and turbo lasers.
The titans' participation instantly changed the balance of power on the ground battlefield.
They brought not only devastating firepower but also unparalleled strategic deterrence.
Even the World Eaters, driven into a frenzy by the Butcher's Nails, began to have their biological instincts override their insane consciousness when faced with such a cataclysmic force.
Chainaxes and bolters could not shake the titans' ankles, and suicidal charges were torn to shreds by dense secondary fire before they could even get close.
They could 'see' that the tide of battle had irreversibly turned.
The frenzied offensive receded like a tide, and the remaining World Eaters began to show signs of breaking, no longer fixated on assaulting the defensive line, but instead trying to find gaps in the titans' destructive barrage to escape this battlefield that had become their grave.
Victory in the ground war was already in sight.
---
Just as the forbidden technology duel between the Mars and Neksum fleets in orbit reached a fever pitch, and Neksum, thanks to Magos Osiris' incredible intervention, was gradually gaining the upper hand, at the edge of this tumultuous battlefield, the veil of space was torn once more.
Without grand announcements or superfluous signals, a solemn and dangerous fleet silently emerged from the Warp like a phantom, its dark hulls seemingly devouring the surrounding light, with massive Maltese crosses and Imperial Aquila insignias appearing particularly grim against the dim background.
It was Sigismund and his Black Templars fleet.
Under the influence of an unexpected Warp storm, they arrived at the battlefield earlier than anticipated.
They completed a battlefield scan with astonishing efficiency.
Sensors clearly outlined the current situation: friendly signals representing Neksum and Osiris' base were fiercely engaging the Mars fleet and the Chaos signals on the ground.
Friends and foes were clear, no further words were needed.
"Lock onto the Mars ships," Sigismund's voice echoed on the bridge of the eternal crusade, cold and resolute, "For the Emperor, for Dorn, destroy them!"
No probing, no warning.
The Black Templars fleet, like a cheetah poised to strike, launched a fierce offensive as soon as it entered the fray.
The massive eternal crusade led the charge, its modified broadside weapon arrays, optimized for close-range destruction, unleashed a torrent of devastation, a volley of lances and macro-cannons striking like a heavy hammer against a Mars battleship that had just struggled free from a spatial compression effect and whose shields had not yet fully recovered.
Simultaneously, numerous Black Templars strike cruisers and frigates, like a pack of wolves, utilized their excellent maneuverability to swiftly cut into the chaotic formation of the Mars fleet's flanks, using dense torpedo and laser fire to slice and surround isolated enemy ships.
The Black Templars' combat style was distinctly different from that of the Adeptus Mechanicus; they preferred to close in quickly, using intense, concentrated firepower to destroy targets in a short time, or... to create conditions for boarding.
Sigismund's decisive entry became the final straw that broke the Mars fleet.
The Mars fleet, already struggling under the fierce assault of the Neksum fleet and the chaos caused by Osiris' relics, was now caught between two fires, its formation completely shattered, and its command links on the verge of collapse.
One Mars ship after another transformed into a brilliant but fleeting space fireworks display under the crossfire of the Black Templars and Neksum.
The scales of victory in the orbital battlefield had now completely and irreversibly tipped in Osiris' favor.
Sigismund's arrival at the crucial moment not only brought powerful reinforcements but also, in an undeniable manner, declared the Imperial High Command's attention to the events unfolding here.
---
Three days of intense fighting finally came to an end.
In orbital space, the last resisting Mars warship was completely torn apart under the crossfire of the eternal crusade and Neksum's Mechanicus Ark, turning into a slowly expanding cloud of metal debris and briefly burning flames, marking the end of this brutal Adeptus Mechanicus civil war with the victory of the Neksum and Black Templars combined forces.
After clearing the orbital threat, Sigismund wasted no time.
He ordered the fleet to maintain maximum alert, then personally boarded a Thunderhawk gunship, and, escorted by a squad of elite Templar Knights, pierced the Death World's thin atmosphere, descending towards Osiris' base.
The gunship landed in a relatively flat area on the outskirts of the base, though still bearing traces of intense combat.
The hatch opened, and Sigismund's tall, black figure appeared at the entrance.
He was still wearing his imposing black power armor, the dust and scattered energy scorch marks on it telling of the fierce space battle that had just occurred.
He wore no helmet, his weathered face bearing its usual solemnity and fortitude, but his sharp eyes, as they swept over the newly formed canyon oasis around the base and the giant spherical crater in the distance, flickered with an almost imperceptible hint of gravity.
Osiris' dark red mechanical body was already waiting at the landing zone.
The massive chassis also bore the marks of battle, with several new scratches and scorch marks on its armor, but overall it still exuded an aura of steadiness and precision.
His crimson optical sensors watched Sigismund descend from the gunship.
The two met against the strange backdrop of scorched earth and new growth, surrounded by busy Adeptus Ministorum Troops and Servitors clearing the battlefield, with the distant, low hum of titan engines faintly audible.
"Lord Sigismund," Osiris' synthesized voice spoke first, steady as ever, "Welcome. It seems your journey was not peaceful."
Sigismund nodded slightly, his gaze returning from the surrounding battlefield relics to fix on Osiris: "Compared to what you have here, a few storms and the obstruction of traitors are insignificant."
His voice was low and direct, "Magos Osiris, I have come at the command of Primarch Rogal Dorn. It is time to discuss the 'future' you promised to reveal."
After many twists and turns, overcoming numerous obstacles, this crucial meeting concerning the fate of the Imperium finally commenced here, on this Death World that had just endured a baptism of fire and blood.