Because everyone's talking about Angron and Kharn
"WHERE IS MY EQUERRY?!" Angron's roaring voice echoed throughout the ship, buckling two bulkheads and killing an astropath within the 'anger zone'. The World Eater's Primarch stormed through the corridors with his head held high, smashing it through several ornate archways as his feet battered and dented the floor with each step like the beating of a war drum.
Captain Khârn of the Fifth Assault Company, Equerry of the World Eaters had been admiring the ornate workings of a dreadnought sarcophagus, a low sigh issuing forth from his helmet as he heard his lord approaching. With a thunderous crash, Angron threw his weight against the loudly snoring construct, sending it bowling into a nearby row of its fellows, knocking them all about like skittles.
"TREACHERY! BLOOD! TRAITORS!" Angron screamed, flecks of spittle splattering all over the equerry's armour, "I'LL HAVE MY REVENGE! IN BLOOD! I'LL KILL HIS FAMILY! ALL OF THEM!"
"What's wrong, my lord?" Khârn asked, his voice low as to not startle his already over-stimulated commander.
Angron thrust a small plastcrete cube in front of the Captain's face, little movable rows covered in coloured squares. Even if it weren't practically being crammed up his nose, Khârn could clearly make out the shapes of Angron's armoured fingers forced into every tile.
"WHO MADE THIS?! I WANT TO EAT THEIR SKULL AND LINE MY BED WITH THEIR BONES! BLOOD!" Angron screamed again, utterly soaking Khârn head to toe in spittle.
"I AM AWAKE?! IS IT TIME TO BATTLE?!" One of the dreadnoughts cried out, the sarcophagus merely wobbling on its side without being connected to its proper frame, as Angron and the Tech-priests continued screaming at everything.
"And that" Khârn the Betrayer spoke to his audience of Red Rivers infantrymen, as he ineffectually plinked a skull full of blood against his mouthpiece and spilled it all down his front, "Is why I decided to start killing everyone"