Orks do not need philosophers.
Even the weakest Gretchin must pick up a blade and join the greatest Waaaaaaaagh! crusade. From the moment they crawl out of their spores, they fight everything around them—breaking someone else's legs or having their own broken. Even the "Oddboyz" must scavenge scrap to forge a crude choppa before heading out to hack and slash.
If an Ork were to ask another, "Why don't we stop to think about why we Waaaaaaaagh!?", that Ork would inevitably be the most "Waaaaaaaagh!" of them all, for he would have to be powerful enough to force others to listen to such a tedious topic. But an Ork that powerful would never ask such a stupid question; they only care about launching bigger, harder, and more "Waaaaaaaagh!" crusades.
"Hahahahahaha!"
Ork Boyz, soaring through the air on unstable jump packs, fired randomly at the ground. There were so many "Umies" that one could hit something just by pulling the trigger. Could there be anything simpler than this?
Killa Kans and Ork Nobz led their mobs in massive, ramshackle "Kill Bursters" and "Battlewagons" made from scavenged parts, surging forward in a grand procession to smash through human lines and bunkers.
"Waaaaaagh!"
It was as the humans had predicted. This was the season of storms; many doomsday volcanoes erupted, sending black clouds high into the sky. Massive Ork armored columns punched through thin Imperial lines. Two tribes moved east of the Palidi Mountains toward Hades Hive, while another tribe moved west toward Hel's Reach.
During this process, the Orks finally encountered enemies truly capable of halting their advance.
The red-robed Tech-Priests of the Adeptus Mechanicus pressed their bodies almost to the ground, feeling the vibrations of the earth as they chanted their hymns.
"Praise the Omnissiah!"
Those priests fortunate enough to participate in the activation of these glorious constructs had already shut down their biological systems. They could not bear to let their weak, organic functions contaminate such beautiful and powerful creations.
Princeps Mannheim boarded his God-Machine.
He knew this was his final battle. He loathed that detestable Planetary Governor—arrogant and obsessed with fame. That Governor believed he could withstand the Ork invasion alone, yet he refused to personally confirm the scale of the xenos threat.
Damn him. Damn him.
The Princeps took his seat in the command throne. He pushed everything unrelated to the battle to the back of his mind. Nothing else mattered now. His only thought was how to command his Titan Legion to crush those weak Greenskins into dust.
"Fuel supply normal." "Systems operational." "Ammunition stores full." "The Machine Spirit is pleased."
With every step, the earth shook under the weight of the Omnissiah's God-Machine.
"Give praise! For now, the God-Machines of the Omnissiah walk upon the earth!"
...
Orks required no communication systems. Their biological instincts found the enemy for them, driving them toward foes worthy of a fight. When the massive Titans appeared on the battlefield, the Orks let out their loudest and most enthusiastic "Waaaaaagh!" yet. All nearby Greenskins swarmed toward them.
Princeps Mannheim listened to the cacophony outside, which nearly drowned out the mechanical roar of the Titan's internal systems. He had fought these brutal aliens before; in his eyes, it didn't matter how many of these weak creatures came.
The Moderati and the Sensor Officer monitored the Auspex. The heat signatures were densely packed, including many massive signals large enough to pose a threat to a Titan.
"Those should be Killa Kans, or perhaps 'Gorkamork' Walkers," Mannheim judged. "We have the superior firepower," he said, "but we are outnumbered. If the rest of the Legion doesn't arrive soon, we're finished here."
"Interesting."
The gunner spotted the silhouette of an Ork "Dakkajet" through the dust clouds.
"Target confirmed," she shouted to the Princeps, her face smeared with grime. Small arms fire hitting the cockpit had wounded her arm, but chemical painkillers injected into her throat kept her sharp.
"Fire at will," Mannheim replied. He used his tongue to check a loose tooth—it must have been jarred when his head hit the side of the throne earlier. He had always been in good health, which was rare for Titan pilots. If he survived this, he could probably pilot for another twenty years.
He felt the angry shudder of the God-Machine as the gunner destroyed an Ork Walker. Then he felt a vibration in the gap between his vertebrae. That was not a good sign.
"Suppressing fire on the perimeter," he ordered. "Turn around. Adjust fire arcs."
The Moderati forced the Titan to turn with a swaying motion. The gunners operated the Gatling Blaster arms, raking the surrounding area. An enemy Ork tank surged into view and fired. The Titan took a hit, and Mannheim felt the pain as if it were his own, hissing through his teeth. Simultaneously, the gunner vaporized the tank into a smoking wreck.
"There are more of them! A Titan has fallen!"
"The Skitarii must be heartbroken," Mannheim muttered. "They are the only ones worthy of fighting beside us now."
He looked across the battlefield. More Orks were arriving, and the Killa Kans and Stompas appearing were growing both in number and size.
"What do we do? The ammunition is depleting too fast. If this continues, we'll be destroyed."
A deafening roar interrupted their conversation. It was the fallen Titan detonating its plasma core. Mannheim realized he no longer needed to explain their ultimate fate.
...
While the Titan Legion and the Orks were locked in battle, thousands of kilometers away, other Ork mobs led by their Nobz were trekking through the treacherous equatorial jungles. These Greenskins had no idea that the enemy they should fear was not on the ground, but in the sky.
"Wot's dis?"
Countless Mycetic Spores rained down. The Tyranids bursting from them caught the Orks completely off guard. However, once the Greenskins realized they were under attack, they became incredibly excited.
"Big bugs! Waaaaagh!"
More Orks swarmed to the area. Within the ruins of the jungle cities, Ork spores began to grow faster, and the Orks grew stronger. To some extent, this slowed the Ork advance on human cities. However, when either the Tyranids or the Orks eventually emerged victorious, the Imperium of Man would be facing a terrifyingly powerful opponent.
This was precisely the plan of Yuki and Yuno, who had already slipped into Hades Hive.