Ignoring their disheveled armor and clothing, they answered in unison, then dispersed like the wind, carrying Sicarius's orders to rally their respective corps and prepare for a battle destined for the history books.
In less than a Terra-hour, the atmosphere across the entire war zone tightened abruptly. The Space Marines of the Ultramarines Second Company, personally supervised by Sicarius, completed their final pre-battle checks. Power packs hummed, Bolter magazines were fully loaded, and the teeth of Chainswords gleamed coldly.
Fighting alongside them, in addition to the fanatical Helldiver corps, were over a thousand Space Marines from various other Chapters. These Astartes, hailing from different fighting units, were unified by a common enemy and their devotion to the Emperor, which forged a single-minded cohesion.
Sicarius stood before the boarding ramp of a Thunderhawk Gunship, his gaze sweeping across the assembled forces. At the front were the elite of the Second Company, who stood like iron-cast fortresses, exuding a suffocating pressure.
Behind them were the surging Helldiver corps and the thousand-plus Space Marines from the brother Chapters, resembling a furious ocean, radiating unparalleled oppressive power.
"For the Emperor! For Humanity!"
Sicarius roared, his voice reverberating through the air.
"For the Emperor! For Humanity!"
The reply was a deafening war-cry—the fury of the Ultramarines, the iron oath of the other Space Marines, and the excited, frenzied howling of the Helldivers.
The large-scale offensive began.
The first move was a full-scale ground assault. The thousand Space Marines from other Chapters, collaborating with the ten divisions of Helldiver corps, launched a frontal attack on the Tyranid outer defenses in an almost suicidal manner.
They formed an unstoppable torrent of steel, surging towards the swarm like a bursting dam. The roar of Bolters, the thunder of Chainswords, the eruption of psychic power, and the desperate charge of the Helldivers instantly turned the surface of Plantidium into a hellscape of blood and fire.
The purpose of this massive offensive was not just to eliminate the swarm, but more crucially, to seize the vast majority of the Tyranids' attention, pinning their senses and forces squarely on the frontal battlefield.
Concurrently, Sicarius personally commanded the Second Company, riding Thunderhawk Gunships, utilizing the advantages of Imperial air space and the stealth of their craft, to execute an ultra-low-altitude penetration. Like a sharp blade, they silently pierced the Tyranid's external air domain.
They avoided the clamor of the frontal battle, gliding like phantoms over the mountains and city ruins ravaged by the swarm, striking directly towards the depths of the Tyranid-controlled zone.
The large-scale and clearly directed Human offensive alarmed the Hive Mind, which issued silent commands. The already rapid writhing and growth speeds of the hatching sacs and bio-reactors under its control instantly hit their limit.
More alien young were birthed, stronger elite organisms were 'awakened' ahead of schedule, and directly thrown into the battle. Flesh and bone rapidly took shape in the darkness, and new claws and carapaces grew through the pulsating mass.
At the same time, the Hive Mind began drawing forces from other regions. The swarms that were previously entangled with Human forces on other Plantidium defensive lines suddenly received new instructions. As if pulled by an invisible hand, their directions of travel began to shift.
On a battle-scarred trench line on Plantidium's surface.
"Ugh, the executive member for our division is utterly useless. We had a guaranteed advantage in that Command Post fight and still lost, leaving us stuck here. We really need to elect someone with better combat power," Pyro complained incessantly while firing at the Tyranid alien in front of him.
Reinhard, beside him, didn't respond to the complaints. The Power Armored warrior was fully focused on making precise, single shots with his Bolter. Each Bolter shell accurately struck a Tyranid's head, utterly tearing it apart. For him, every second on the battlefield was precious, allowing no room for distraction.
Just then, the intensity of the Tyranid attack in front of them suddenly and noticeably diminished. The swarm, which had been pouring in like a tide, suddenly became sparse, and the frequency of attacks clearly dropped.
This perplexed Pyro: "What's going on? Is the offensive ending already? Did the Tyranids get tired or something?"
"No, that's wrong," Reinhard's voice was low and calm. "Based on past experience, the Tyranid attack usually intensifies toward the end of a wave for one last push. This sudden reduction likely means the Tyranid forces here have decreased."
"Could the pressure over there be too much, forcing the Tyranids to redeploy?" Pyro's mind raced, quickly connecting it to the deep-strike plan by Sicarius and the Second Company. "Holy crap, the brothers actually pulled it off! The tactic worked! So what are we waiting for? Let's charge out and counterattack!"
His eyes gleamed with excitement, as if he saw a perfect opportunity to farm prestige.
But Reinhard countered: "What if it's a trap? You and I both know how cunning the Tyranid swarm is; they are very skilled at tactics like feigning retreat to lure us in. Charging out rashly could easily lead to an encirclement."
"Who cares? So what if we die? It's not the first time!" Pyro waved the Lasgun in his hand dismissively.
Like Pyro, the Helldivers across other areas of Plantidium who also felt the reduction in the Tyranid attack intensity made the same choice. They didn't bother to consider the possibility of a trap; in their view, the reduction in Tyranid forces was the perfect time for a counterattack.
"Charge! The Tyranids chickened out!"
"Kill all these bugs!"
Accompanied by thunderous battle-cries, the Helldivers on every front line charged out like horses running wild. They launched a counterattack without hesitation. Relying on their astonishing resilience and nearly infinite respawns, they turned into torrents of fanaticism, bursting out of their defenses and engaging the retreating swarms.
While the Tyranid Hive Mind faced a critical threat in its core zone, it also had to deal with these 'crazed' mortals. To stabilize these regions and prevent a total collapse of the battle lines, it was forced to draw more, even more distant, forces to reinforce these areas, accelerating the production of new units in an attempt to extinguish these sparks of 'counterattack.'
However, the further redeployment of Tyranid forces triggered attacks from even more Helldivers who were 'emboldened' by the reduced Tyranid attack intensity.
In this cycle, without any proactive planning from the high command on either side, the entire vast battlefield of Plantidium—involving hundreds of thousands of Space Marines and millions of Helldivers—suddenly descended into a total war driven spontaneously by the players on the ground.
Even Sicarius himself, who initiated the deep strike, probably hadn't expected that merely mobilizing ten divisions of Helldivers and over a thousand Astartes Space Marines for an assault would completely churn up the entire strategic situation on Plantidium. The defense and counterattack, which had been somewhat orderly, instantly devolved into a chaotic, large-scale melee.
This kind of disorganized, self-driven conflict, lacking unified planning, was vividly described in the after-action report submitted to Calgar: "The entirety of Plantidium has devolved into a complete mess."
And while the Human high command was racking their brains over this mess, the Hive Mind controlling the swarm also encountered an unprecedented crisis:
It was running out of Biomass.