Killkrumpa Weirdblitz charges through the fire of the yellow Space Marines like it is little more than rain. He has shrunk himself down to twenty feet tall for better mobility inside the 'umie ship, but he hits just as hard as four of the Space Marines find out immediately. He smashes one in the chest, vaporizing his torso or sending it into Warp; Killkrumpa stopped caring, which was a while ago. At the same time, he takes the head off a second and scoops up a three by his head before throwing him like a missile into a fourth. These 'umiez are not like the half-machine men; they are the best their kind has to offer, and they come at him hard. Killkrumpa comes harder.
They fan out, still firing, and some charge in with roaring choppas and power fists. They are fast and unleash everything they can at him. He grins under his mask as he shows them why he is the Biggest Boss. He came alone and decided to only use his fists on purpose; he wanted to have all the fun he could. One comes at him with a powerfist. Killkrumpa uppercuts him into the ceiling. Another comes in with a two handed chainsword, he spins and boots him into a wall. Someone fires a plasma gun at him, which splashes over his Warp shield harmlessly. Killkrumpa roars and fires searing green breams of Warp energy from his eyes, which are forced through his mask lenses. They cut ten Space Marines in half, along with the weapon shelves, deck, and wall around and behind them. They must hit something volatile, another new word in his growing vocabulary, because that side of the arming deck explodes, taking twenty more Space Marines with it. The force of the explosion throws most of the others to the deck. It doesn't budge Killkrumpa, who just laughs as he continues the slaughter.
The Space Marines continue to fight; not used to being this outmatched, they attempt to rethink their strategy, only they don't have time. Killkrumpa is too fast, too powerful, and too mean for them to take a single breath to regroup. In the end, it is the two weirdboyz whom they call psykers among them who allow their remaining battle brothers, who number Less than twenty, to escape. The two psykers step up and unleash a barrage of Warp lightning and fire on Killkrumpa. This attack forces him back a few steps, letting their brothers run like the wimps they are. The attack is powerful and would likely have killed most other enemies, but Killkrumpa is not most enemies. He is the Biggest Boss, and everything, even the Warp, will bow down.
He retracts his mask and breathes in, deeply absorbing the unleashed Warp energy like it is a breath of fresh air. At the same time, he pulls all the psykers' remaining Warp energy from their bodies, leaving them gasping on the deck. Then he gives it all back to them in a tide of green flames that cooks them body and soul. The flames consume the arming deck, which explodes. The explosion blasts through several other decks, spilling green Warp fire through all of them. Killkrumpa walks through the burning halls without care other than finding his next fight.
He has spent several minutes swatting the ship crew when it appears in the form of several Space Marines wearing what looks like Ork Mega Armor. KillKrumpa knows they call it Terminator Armor, and it is worn by their best. The one who he would guess is their leader charges him with powerclaws crackling. He apparently wants to fight Killkrumpa on his own. Killkrumpa is more than happy to grant his wish. He charges forward, faster than the 'umie was expecting, and meets his slashing claws with a closed fist. His fist wins as the claws break against them, along with the Space Marine leader's arm. His fist catches him in the chest, and the force of the blow, along with the discharge of his broken claws, sends the Space Marine flying, him and his armor broken.
Seeing this and watching as the other Space Marines move to defend their fallen boss, Killkrumpa stops. He could charge through them and krump all of them, but what was the point? He just krumped their best with a punch. He laughs at them before turning and walking away.
"I guess I heard wrong," says Killkrumpa without looking back at them, "You aren't worth the time it would take to krump ya. So, I'll give you a job instead. Run away and tell your Imperium that Killkrumpa is here and the Biggest Boss is looking for a fight. You can bring it to me, or I will bring it to you. Bring someone worth my time. Maybe wake up that Empera of yours off his pretty throne."
He is still laughing he a Warp portal opens before him, and he leaves the Space Marines behind to go and find another fight. Theirs is the only ship the Orks don't take or destroy that day.