"Sergeant, leave it to me!"
The Tyranids surged forward like a tidal wave. Tyranid Warriors, clutching massive Venom Cannons, aimed at any enemy attempting a direct strike on the Tyrant. Heavy Tyrant Guards remained steadfast, loyally fulfilling their duty to protect.
The Hive Tyrant—the direct executor of the Great Devourer's will—acted as a synaptic creature, commanding all lesser organisms on the battlefield. The Aether Fleet possessed a much higher proportion of elite bio-forms than standard fleets, a compensation Yuno had designed to make up for their lack of raw numbers.
The sub-commander looked at his volunteering battle-brother. At this point, only they could make such an attempt. "Go. The Chapter will be proud of you."
The Assault Squad, utilizing jump packs to achieve supernatural mobility for decapitation strikes against priority targets, was a standard Space Marine tactic. The sub-commander saw more Tyrant Guards scrambling over the ruins, seeking leverage to replace the Hive Tyrant in supporting the collapsing temporary structure.
If that Hive Tyrant was freed from its structural burden, this position would be lost instantly.
Under the covering fire of their brothers and mortal soldiers, the Jump Pack Squad leaped into the air. In a twelfth of a second, they aligned with their target and ignited their thrusters once more.
Almost simultaneously, the Hive Tyrant let out a bone-chilling roar and charged out of the ruins, its bone-swords held defensively as it slammed into the squad mid-air. Three Astartes were sent flying. With the Tyrant Guards and other Tyranids now bracing the rubble, more and more of the swarm poured inside.
The sergeant had to make a call. "Orderly withdrawal! Minimize casualties! Fall back to the pre-prepared fortifications!"
The main tunnel had held out the longest; other objectives had been overrun by the Tyranids almost instantly.
...
Aside from the Tyranids, the city still harbored a vast number of Chaos cultists, who remained a significant threat. Enos had abandoned the defense of secondary targets, following the Codex to establish a formidable defense within the core district. In the brief time bought by those at the perimeter, he had to purge the internal Chaos elements.
Leading several Exorcists, he turned into an alleyway and ran straight into Yuki.
"Yuki? How are you still alive?" Enos realized something was wrong immediately, his finger tensing on the trigger. The Krieg regiments stationed outside the city had been nearly wiped out; how could this human have survived the Tyranid onslaught? Recalling why he had investigated Yuki in the first place, suspicion was inevitable.
Yuki shouted frantically, "Quick! There are Astartes behind me! They're attacking me!"
Enos's attention shifted for a split second as he noticed several Iron Warriors not far behind. How are there Iron Warriors hiding in here too? Enos acted decisively, his bolter barking at the Iron Warriors, who returned fire without hesitation.
Strangely, however, the Iron Warriors didn't aim for Enos, even as his bolt shells struck their helmets. Their entire volume of fire was concentrated on Yuki.
Enos saw a ripple appear behind Yuki, deflecting the Iron Warriors' bolts. An unsanctioned psyker? Before Enos could react, a sharp bone-blade extended from Yuki's arm. However, a plasma blast from an Iron Warrior struck Yuki, tossing him backward. Yuki used the momentum to smash through a nearby wall and vanished into the darkness.
Before Enos could process what had happened, the Iron Warriors retreated rapidly. He hesitated for only a second before barking an order: "Immediately hunt down that non-human! That is our primary objective!"
In the face of the Xenos, the Exorcists and the Iron Warriors followed their genetic instincts, setting aside their divide to face the Tyranids. Neither side would ever admit to such an alliance; they would tell themselves it was merely a rational choice based on the tactical situation. After all, when all was said and done, they were still human.
For Yuki, who was no longer human, the failed ambush was a major complication. He hid in a narrow crevice, successfully evading the Exorcists' search.
"Dammit, I got outplayed by those Iron Warriors." This body's physical strength wasn't comparable to the one Yuki usually used, and controlling two bodies simultaneously made his movements less fluid. Being able to retreat after killing a few of them under heavy fire in a narrow corridor was already a feat. "What bad luck. The defenses here are terrifying. If nothing changes, this is going to be the hardest nut to crack."
Yuki shifted his primary focus back to the main swarm.
"Mmh."
"What's wrong?" Yuno asked.
"I've been exposed. If possible, it's best to annihilate everyone here. No one who knows about me should be left alive."
Yuno stroked Yuki's head as if soothing a pet. "It's fine. Sooner or later, I will let the whole universe know of your existence."
"Then let's make the swarm even more aggressive."
As the two kissed, the swarm erupted with a startling surge of subjective initiative. Pleasure, excitement, happiness, and joy—emotions that didn't belong to the Tyranids—spread through the universe via the Hive Mind network. Anyone standing against the Hive should regret having to fight them at this moment. As Yuki and Yuno's passion reached its peak, the enemies of the Hive stood before a swarm made even hungrier by intense bliss.
...
Enos had to find a way. The Tyranid threat was inching closer; they needed time, they needed power. Unknowingly, he found himself alone in the shadows. From those shadows, several figures spoke.
"Lapdog of the False Emperor."
Enos drew his weapon, aiming it at the Iron Warriors.
"Do not display your stupidity here. Much as I loathe saying it, we need to cooperate."
"Traitors! I would sooner die than work with you!"
"The fact that you didn't fire the moment you saw us proves you've already made your decision," the leading Iron Warrior said darkly. "Through the power of the Infinite Heavens, we see the thoughts in your heart."
"Shut up! Do not try to tempt me!"
"We have a way to break through the Tyranid's Shadow in the Warp to call for reinforcements. But it requires your help." The Iron Warrior paused. "We need the key to the subterranean pulse system. You have it on you. Believe me, I took a great risk in making this decision."
"You plan to call your comrades!"
"And you can call yours," the Iron Warrior replied haughtily. "Lapdog, do you really want your battle-brothers and the remaining mortals to become biomass for the swarm?"
Enos stood frozen. After a long silence, he unclipped a small data slate and threw it to the Iron Warrior. "Never appear before me again."
The Iron Warriors vanished. Enos felt as though his mind were breaking. Had he been influenced by the powers of Chaos? What had he just done?