I can't wait to see Mattheus' "epic strategic victory" in this situation.
Yeah, it's tricky. Root's got a few options here:
A) "I regret only that I have but one guardsman to give for my Emperor," remarks Matthaeus, bravely tossing the corporal's screaming body into the mutants and charging in the opposite direction.
B) Matthaeus notices the flicker of shadow a moment too late. The mutant's claws are snaking toward him, impossibly fast--only to be stopped by the body of a brave corporal, who gives his life that his Spiritual Liege might live. The Brother-Librarian dispatches the mutant with a swing of his staff, then looks to his fallen comrade in arms. The man is convulsing, likely about to turn. "Any last words, guardsman?" he inquires, raising his force-staff to administer the Emperor's Peace.
"Now . . . I will never . . . be an Ultramarine," the corporal whispers, his face full of regret.
C) "Good man," Matthaeus says, clapping the corporal on his back and knocking the wind out of him. "Hold fast. There is only one maneuver that can save us now." The Brother-Librarian pulls out a small rectangular object and seems to fall into a trance, reflecting in it. The corporal is left alone, facing the six dark shapes in front of him.
Swearing softly, he levels his bolt pistol. Well, he'll do his best.
He takes aim. They come.
BLAM!
One mutant falls, claws clutching at the empty air that suddenly fills the center of its forehead.
BLAM!
Another mutant halts, stopped dead by a blast that separates the left side of its chest from its body.
BLAM!
A third mutant goes down, snarling as the corporal's shot severs its legs from under it. But now the three last mutants are almost upon him. It was a good try, but he won't have time to reload.
Matthaeus's voice rings out behind the corporal. "Multiple--"
A huge metal cannister drops from the sky, crushing one of the creatures.
"Simultaneous--"
A second drop pod erases all evidence that another mutant had ever tainted this world.
"And Devastating--"
A third drop pod annihilates the last of the mutants.
"Defensive deep strikes!" Matthaeus proclaims triumphantly, as a fourth drop pod lands and turns the corporal's body into a grease stain. A brave-looking Ultramarine steps out, looking sheepishly back at the the drop pod. "Was that one of ours?"
"No worries, brother," said Matthaeus, "To each of us falls a task, and all that Steel Rain requires of guardsmen is that they hold the line and die standing."