Some might think, 'Oh, a Swarm Overmind using Infested instead of actual Zerg to fight? How pathetic~~~'
However, infestation has its own unique merits.
The mutations resulting from the fusion of Zerg genes with other organisms' genetics—in Abathur's view, this is glorious 'evolution.'
Discard useless genetic sequences, incorporate Zerg genes—efficient, stable, orderly. The varied outcomes of infestation also serve as experimental specimens for Abathur.
†Seems the Golden Age and Dark Age didn't give humanity many genetic locks. Infestation spreads quickly. Useless against Space Marines, though.†
Not a physiological issue. Space Marine respiratory systems are self-contained, and they rarely remove their armor. Zerg virus cannot infect armor-clad Astartes.
†Come, Genestealers. Let's see whose numbers are greater.†
The Swarm Overmind already knew substantial Genestealer forces were entering Izsha's territory. Frontline Infested were rapidly eliminated; before death, they witnessed numerous Genestealers and armored vehicles.
†Bringing armored vehicles into the Underhive? You're ruthless. Ruthless even by Darktide standards!†
Admittedly, armored vehicles are formidable.
No matter. The Overmind had more people—more than their entire faction.
†Sacred F2 connects us all. JUST A-MOVE THEM!!!†
Vast Infested formations traversed every route to the Underhive. Underhive residents, waking to this spectacle, rubbed their eyes, confirmed their vision, shrugged, and resumed slumber.
"Must be hallucinating. Even for the Underhive, this is impossible. Mutant armies don't just march."
Genestealer Cult members remained utterly unaware that while encircling Izsha's territory, a far larger encirclement was encircling them.
"FIRE! FIRE!"
Centaur armored vehicle turrets opened fire, effortlessly shredding Zerglings and Infested. A Genestealer gunner in the commander's seat raised his boltgun, emitting arrogant laughter.
"Hahaha! Tear them apart! SHRED THEM! Reduce them to pulp!"
Hunters held back. Even Hunters would struggle against a Centaur's heavy bolter turret, not to mention the triple lascannon array and heavy flamer forward. That heavy flamer alone was impassable for Infested.
Moments later, however, a tail spike extended from darkness, piercing the Genestealer commander's cranium. The Genestealer immediately turned his weapon inward and sprayed the compartment.
Another Infestor contribution.
When hybrid Genestealers regained awareness, that Centaur was again firing—this time targeting Cult members, not Infested.
"AAARGH!"
"DAMN YOU! WHO ARE YOU SHOOTING?!"
Hunters seized the opportunity, engaging remaining Cultists and the armored transport. The unfortunate Centaur's frontal hull was perforated; its sole Genestealer commander likely perished.
The infesting tail spike retracted.
Without the armored vehicle, Cult members in this conduit were routed. Retreating to other passages, they discovered their ingress routes already blocked by vast crowds of mutated Infested.
"When did they arrive?!"
"It's over!!!"
"So many..."
Surrounded Cultists could only wage a final firefight. But against Infested swarms plus pursuing Hunters, their ammunition couldn't match Infested numbers. Predictably, they were annihilated.
Infested then boarded the Centaur, incorporating it into Swarm assets. Creep spread across its hull. Regardless of Machine Spirit acquiescence, Creep-infested transports would become new combat assets.
Similar scenarios unfolded throughout the Underhive. Genestealer Cult members suddenly discovered mutated Infested everywhere—endless, omnipresent, practically flooding the Underhive.
†Hive World edition: Night of the Walking Dead commences. Unless you're the four Emperor-chosen from Darktide, you'll drown in Infested!!!†
Infested Imperial civilians numbered too many. Genestealers were forced into melee.
Once drawn into melee, Genestealers held zero advantage.
A Cultist would slay one Infested, only to be impaled by sharp bone spurs from several others. Infested defense was frail, but their offense could penetrate second-generation hybrid chitin.
This was a prolonged war of attrition. The Swarm Overmind was thoroughly enjoying himself.
The Genestealer Cult chieftain, however, was far from pleased.
Genestealers possess a hive-mind-like group consciousness—psychic communication and coordination. The chieftain sensed individual kin thoughts extinguishing at an alarming rate.
"What manner of xenos are these?! Such tenacity!"
The Cult, traditionally dominant in the Underhive, found itself at a disadvantage—unfathomable to the chieftain.
"Whatever they are, they cannot usurp our territory. Release the Aberrants. Deploy other Patriarchs. We cannot cede further ground."
Patriarchs refer to diverged Purestrain Genestealers, weaker than the original Purestrain.
Aberrants: mutant Genestealer variants. Larger, more powerful than standard hybrids. Their developed muscles allow effortless wielding of extremely heavy mining tools.
Power mauls—heavy bludgeons with built-in force field generators that disintegrate struck matter. In mining operations, these tools easily shatter rock.
Of course, a single tap can also rupture Space Marine power armor.
The Genestealer Cult deployed its high-end assets. Patriarchs, leading Cultists and Leman Russ tanks, began wholesale Infested slaughter. Infested autoguns proved incapable of penetrating Patriarch armor or tank plating.
They advanced unstoppably, carving a bloody path through Infested ranks.
Aberrants, like flesh behemoths, rampaged through Infested crowds. Their power mauls and power picks were utterly irresistible. One unfortunate Hunter, failing to evade, had its skull shattered by a single maul blow.
†Holy crap! What ARE these?! Never seen them?!†
Aberrants indeed touched upon the Overmind's knowledge gap. With ten editions of Warhammer rulebooks, who can memorize everything? Presumably, scoring 90+ on the a test would be effortless.
†Formidable. Come, Infested Centaur. Test yourself against this one. See who's more formidable.†
Minutes later, an Infested Centaur confronted the Aberrants. Though immensely strong, Aberrants possess... limited cognition. They charged the Infested Centaur, power mauls and picks raised, bowling over intervening Infested.
†FIRE!†
The Infested Centaur's turret opened fire. Heavy bolter fire instantly pulverized one Aberrant's head and perforated another's chest.
†Infested vehicles are just better.†