Oberon raised his bolt pistol in time to meet the airborne charge of a howling mutant. It was an insane thing, with skin like poorly aged leather, no eyes and far too many mouths. It gibbered inanely as it bounded over the heads of its equally depraved fellows with speed that belied its spindly frame. Only to be blown out of the air as a bolt shell barked and took it full in the chest. It struggled to rise with this new and vast bloody crater taking up most of its torso but eventually collapse again, reduced to a slow death as it bled from its considerable wound. 

Oberon didn’t spare another shell to put it out of its misery. Content to let it die, mewling and pitiful. Better for it to suffer for its shameful existence than to waste holy munitions to expedite the inevitable.  His fellows were not as precise in the expenditure of their energies. Shouting warcries and litanies, were these proper foes, which is to say traitor astartes or similarly high profile threats he could well understand. But these were mere chattle, mutants and hate-spawn that needed little of of the grandstanding these brotheren were indulging in. 

He stood behind his brothers, But in front of the valuable servitors. The battle servitors were unable to open fire with the roar of their integrated heavy bolters. The IFF signals of the battle brothers standing in the way halted their marksman sub-routines unless Oberon overrode them manually. Though tempted to do just that if it meant bringing this pointless conflict to speedy conclusion, he kept their guns silent. This skirmish was just that, nothing more than a waste of time on the path to his goal, hardly the kind of battle that legends were carved from.