"Where in the name of the stars did these cursed constructs come from? Are they the lingering remnants of the Old Ones from the War in Heaven?!"
The crowned Lord snarled with uncharacteristic fury. He had detected the roiling Warp energy moments before, yet never in his ancient engrams had he anticipated it spitting out a host of entirely soulless war machines. Furthermore, the profiling of their heavy weaponry bore absolutely no resemblance to the elegant wraithbone craftsmanship of the Aeldari.
Vibrant emerald light flared within his oversized singular ocular. Raising his staff high, he leveled it at the Armored Wardens currently locked in close-quarters fury with his Hexmark Destroyers and Skorpekh Destroyers.
Beneath their feet, the rocky terrain began to violently heave.
Boom!
Dozens of massive, centipede-like Canoptek constructs erupted from the fractured crust. These were Canoptek Tomb Stalkers, specialized guardians engineered to purge the subterranean depths of tomb worlds.
These gargantuan, living-metal myriapods were autonomous machine-constructs, sharing a basic architectural lineage with standard Canoptek scarabs. The sole distinction lay in their horrific scale; even the largest combat scarab was barely a tenth of a Tomb Stalker's size. They served as the Necrons' super-heavy vanguard, their segmented forms stretching over a dozen meters in length.
The countless interlocking metal limbs lining their flanks served as lethal scythes while granting them unparalleled, liquid agility across the broken earth. At their fore, their horrific heads were mounted with composite gauss weapons and a pair of monomolecular flaying claws, ordnance capable of shearing through heavy armor while inflicting catastrophic flesh-trauma.
Screeech!
The deafening screech of grinding metal rang across the front lines. The Armored Wardens were instantly swarmed and overwhelmed by the sheer mass of the Tomb Stalkers, whose living-metal chassis possessed terrifying, crushing strength. Under the constriction of the segmented horrors, the silver frames of the wardens buckled, shattered, and detonated with earsplitting reports.
Boom!
Yet, as the Tomb Stalkers began to uncoil their long bodies from the wreckage, catastrophic detonations tore outward from within the ruined frames of the fallen automatons. Since expanding his standing legions, Axion had rarely resorted to such pyrrhic, self-detonating combat protocols. But against the Necrons, even the ancient machine-intelligence found itself pushed to employ harsher measures.
In an instant, the valley resembled a grid-coordinated saturation bombardment. Seething shockwaves and volatile firestorms swept across the dirt. Several Tomb Stalkers were completely vaporized by the localized explosions, their shattered hulls scattering into razor-sharp shrapnel. Others sustained only minor abrasions to their living metal, while a handful of unfortunate Aeldari squads caught in the crossfire were obliterated.
Axion did not care.
The ancient pact between the Federation and the Aeldari Empire was rife with hidden ambiguities and protocols. The Iron Men harbored no true empathy for the survival of the xenos; they were merely executing a cold contractual obligation. Without the presence of Imperial forces, who were explicitly shielded by the protocols, the machine-intelligence fought with absolute, remorseless disregard for collateral damage.
Amidst the inferno, Yvraine stood frozen in sheer awe. Flanking her on either side were two towering machines identical to the personal guard that once accompanied Axion. Their massive alloy shields were fully deployed, their heavy energy fields overlapping to form a hemispherical aegis that domed over her like an inverted bowl.
Through the narrow gaps in their armor plating, Yvraine watched as an endless hail of shrapnel rippled harmlessly across the Aegis Protectors' energy barriers.
"Signal transponder array signature authenticated," one of the Aegis Protectors intoned, its head pivoting a full one hundred and eighty degrees to face her, speaking in flawless, archaic Aeldari. "Identity verified. Query: Ynnari leader Yvraine, this beacon was originally entrusted to a Troupe Master of the Harlequins. Detail the parameters of your possession."
"I encountered a Solitaire of the Troupe," Yvraine replied over the din of explosions. "It was he who surrendered it to me."
The Aegis Protector's optical sensors flickered with a cold, pale light before it gave a stiff nod. Axion had no interest in why the Aeldari were engaged in a bitter war of attrition with the Necrons, nor did he care why they were being driven to the brink of annihilation. So long as the core directives of the pact were fulfilled, the nuances of xenos survival were irrelevant.
"The Iron Men shall assume total operational control over this theater. You are cleared to break contact. The pact is being honored; until the cessation of hostilities, maximum tactical assistance will be extended to your person."
Shielded by the immovable bulwark of the Aegis Protectors, Yvraine wasted no time. She barked orders through the psychic web, commanding her scattered forces to consolidate, disengage, and cede the battlefield to the iron legions.
As the Aeldari scrambled to retreat, new blinding cascades of Warp-displacement light fractured the atmosphere. A massive payload of Adaptive Combat Cores was deployed into the heart of the fray. These nanite-spheres were dropped in concentrated clusters, instantly liquefying and fusing together. Within the roiling sea of quicksilver, colossal metal gun-turrets rapidly materialized.
Zz-fazz!
The mass coalescence of the nanite-constructs made them an impossible target to miss. Dozens of heavy gauss beams slammed into the swelling mounds of silver. The dense, emerald rays punched clean through the forming structures, dissolving vast swathes of material into drifting clouds of severed atoms. Yet, with a sudden, localized distortion of reality, the dissolving particles snapped out of existence, and the sheared matter reformed instantly. The Spatiotemporal Solidification Units integrated within the Adaptive Combat Cores functioned flawlessly, rendering them immune to the molecularly disruptive effects of the gauss fire.
From the apex of these fully formed amalgams, barrel assemblies stretching over ten meters extended outward, unleashing blinding beams of apocalyptic energy. The incandescent amber lances rivaled the raw fury of Nova Cannons, eclipsing even the Volcano Cannons wielded by the Imperium's God-Machines. Violent kinetic and thermal shockwaves ripped across the basin, scourging the earth. Cohorts of Necron Warriors, Immortals, and Skorpekh Destroyers were utterly annihilated, while Doomsday Arks and Lokhust Destroyers were detonated into expanding crowns of scrap metal.
In response, several massive hyperexponential tears split the skies. A terrifying matrix composed of six towering Doomsday Monoliths drifted forth from the trans-dimensional folds, holding formation directly over the Necron lines.
With a violent thrum of dynastic power, the monoliths retaliated. Whipping tendrils of raw particle-energy lashed down from their pyramidal crowns, striking the nanite-fused turrets and smashing them into microscopic dust. The sheer energy yield generated by these monolithic structures was staggering even by Necron standards; within Imperial archives, these very weapons held a dark notoriety for shattering Warlord Titans with a single discharge.
Yet, such devastation was not absolute against the Adaptive Combat Cores. As their Spatiotemporal Solidification matrices flared once more, the colossal fused turrets reconstituted themselves from the atomic mist, answering with their own blinding beams. This apocalyptic exchange of reality-warping ordnance filled the retreating Aeldari with absolute dread, while aboard the Void Sword, the watching Primarchs stood dumbfounded by the terrifying scale of the conflict.
In the next heartbeat, an even more gargantuan dolmen gate expanded across the atmosphere. A terrifying macro-construct broke through the trans-dimensional breach. Blinding emerald particle-streams erupted from the rapidly solidifying colossus, instantly enveloping one of the giant nanite-turrets.
When the beam, spanning dozens of meters in diameter, finally dissipated, the target was gone. The core nanite-kernels of the multiple Adaptive Combat Cores inside the structure had been completely atomized in an instant. Spatiotemporal Solidification could no longer trigger, and the surviving nanites dissipated into the wind like gray ash.
Aboard the Void Sword, the four Primarchs gazed upon the Necron super-structure with a mixture of horror and bewilderment. For all four of them, this was the first time they had truly witnessed the unmitigated, apex terror of the Necron dynasties. Though their Chapter gene-sons had waged countless shadow wars against the undying metal legions over the millennia, the Primarchs themselves had rarely traded blows with them directly.
Axion's systems instantly profiled the gargantuan entity: it was a Megalith.
Though the standard databases of the Imperium contained but a single, fragmented record of a Megalith, its lethal pedigree was absolute. During the conquest of Uttu Prime in the closing years of the 41st Millennium, Nemesor Zahndrekh, another crowned general whom Axion had previously cataloged, had deployed a Megalith to the theater. In that singular campaign, Zahndrekh's legions had entirely annihilated three Catachan Regiments alongside three full Vanguard Companies of the Imperial Fists Chapter. From that dark day forward, the Imperium had adopted a doctrine of strict evasion; the moment a Megalith silhouette was confirmed on a world's surface, all remaining forces were ordered into immediate, planetary evacuation.