Clumsy.
Heavy.
Slow.
Unstoppable.
These concepts filled the Hive Mind's thoughts as it realized that a prolonged war of attrition would end in inevitable loss. Engaging in a pure, head-on clash on the open plains would only hasten defeat. These iron bodies were like many war machines the Swarm had encountered before: precise, cold, and reliable, always with a variety of preset responses to face new situations. Yet, the Iron Warriors were even more exacting, colder, more dependable, and armed with even more methods of counterattack.
Due to their inorganic nature, the Iron Warriors could employ combat strategies that seemed self-destructive, yet were anything but. However, the entity controlling them appeared overly reliant on the inherent characteristics of these metallic bodies. Their weight prevented them from employing agile tactics, which the Hive Mind saw as a potential weakness.
With its analysis complete, the Hive Mind devised a strategy. A portion of the Swarm split from the main body, maneuvering through the land formations to flank the Iron Warriors. Flying beasts that had previously swooped upon the Iron Warriors to no avail now served a new role, acting as decoys to distract them.
Initially, the tactic yielded results. Led by twenty Tyrants, billions of Swarm creatures breached the Iron Warriors' flank, surging forward before the machines could react. As before, the Iron Warriors did not falter or adjust their tactics in panic; they continued advancing, unleashing arcs of lightning and combustible gases to decimate the encroaching Swarm with indiscriminate efficiency.
This time, however, the Iron Warriors paid a price. Caught off guard, at least a hundred thousand Iron bodies were dismantled by bio-weapons, leaving only fragments of data streams that retreated to the mothership for rebirth.
"Clever."
The primary AI offered high praise, conceding its own unfamiliarity with battlefield strategy. Since its creation, the Leviathan Mothership had fought only twice: once against the Plague Walkers, and now, against the Tyranid Swarm. With limited data, the AI had yet to devise comprehensive tactics. However, as an artificial intelligence, it possessed distinct advantages.
"Retrieve combat data."
"Set directory category to: The Battle of Cadia."
"Limit scope: Lord Castellan Creed."
"Data, imported."
In an instant, torrents of data flowed into the AI's core, transforming it, as though bestowing upon it a new mind—a tactical genius. All these records were drawn from the Battle of Cadia, from the command archives of Lord Castellan Creed, who had orchestrated combined forces against the Terran army. The Terran soldiers' power armor had recorded his commands, creating a replicable model in their data storage. With Creed's model, the AI's thoughts sharpened, and within mere seconds, it enumerated every conceivable tactic the Tyranid Swarm might deploy, along with countermeasures.
Though Creed had never faced the Swarm nor the Iron Warriors, the data model speculated on how he would confront such foes, imagining his strategies both as the Swarm's commander and its opponent. Every possible tactic the Swarm might employ was mapped out. Certain units of Iron Warriors were then deployed, positioned to intercept any future attempts.
The Hive Mind observed these adjustments, noting, for instance, a cluster of ten thousand Iron Warriors stationed mysteriously four hundred kilometers to the left of the main force. Such anomalies were scattered across the battlefield, and as the Hive Mind prepared new strategies, it found that each one had already been anticipated by the enemy. Those strategically positioned Iron Warriors thwarted every potential maneuver, reducing the conflict once more to a mindless, attritional struggle.
In this brutal standoff, the Tyranid Swarm and the Iron Warriors clashed like two colossal titans, each strike met with another, a test of endurance where victory would belong to the side that could endure the longest. For the Hive Mind, this ceaseless drain of resources bred a faint despair; the opposing predator appeared almost tailor-made to counter all organic life. Their deaths left no bio-mass, and they guarded against any reclaimed resources falling back into organic hands.
While previous foes had been difficult due to decapitation strategies, the Iron Warriors posed an even more formidable challenge. The Hive Mind might have an endless supply of bio-mass, but victory against this relentless foe remained uncertain.
However, the Hive Mind realized that while tactics and bio-mass collection could be restricted, it retained one edge the Iron Warriors could not suppress—evolution. After another synchronized bout of synaptic contemplation, the Hive Mind saw two paths for adaptation.
First, it could evolve its units with chitin armor that negated arc weapons. The flaw in this approach was twofold: fully armored creatures would lose sensory abilities, though this could be overcome with guidance from higher synaptic creatures. More troubling, however, was the increased bio-mass cost. Should the enemy's weaponry evolve further, defeat would only hasten.
The second path was to evolve more agile, lightweight units with enhanced bio-dissolution fields. Abandoning defense entirely, the Hive Mind could create creatures capable of slicing through the Iron Warriors' bodies, hoping to overwhelm quickly. Yet, this approach had its risks—if the new creatures failed to gain an early advantage, they would be decimated.
After brief deliberation, the Hive Mind chose a dual approach, incorporating strengths from both options. Leaving a small number of creatures to delay the enemy, the Swarm retreated to the digestion pools. There, new forms emerged: creatures with minimal armor but potent enough to sever Iron Warrior bodies, while warrior-class creatures developed fully chitinous shells.
To reclaim resources from their adversaries, the Hive Mind also endowed its gathering units with the ability to consume metal. Although insufficient for crafting entire war beasts, the scavenged materials could at least reinforce their armored shells.
The Swarm's tactics shifted accordingly. Tyranid beasts ceased direct confrontation on the plains and burrowed deeper, carving tunnels that allowed their approach under cover, securing precious moments before encountering the Iron Warriors' lethal arc weapons.