The first kill was with a bolter, but after that, he moved to his chainsword, cutting with a controlled fury and economy of motion. Nothing was wasted. It was the lesson he learned in the Heresy's opening days, to conserve everything he had. The bolter fell into place on its harness and the chainsword started up with a roar. It shredded flesh and made a mess, but it did the job. Even with the promethium that fueled the chainsword, he was absolutely careful to use the minimum to get the job done.

If the first few soldiers that died were easy kills due to the element of surprise, things got tougher when someone set up a firing position in the chamber and started firing grenades from a launcher, the automatic kind used by the Solar Auxilia, at the Astartes. His own armor was inefficiently cooled and the output was turned down, which was galling in the sense that he was used to moving faster. His armor bore him through the fighting he did on Polybius, so he valued it. But he had to repair it already and the efficiency was down from the peaks he knew when there were sufficient specialists in his legion to maintain equipment. Still, it was fast enough to let him take cover when the grenades started hitting nearby. It was strong enough to protect him from the shrapnel that flew about. The ceramite withstood that test, even if it was degraded from prior service and insufficient maintenance.

With the grenades coming down around him, there was limited time. Someone had to get that grenadier. Working his way through the cargo containers in the area, using the cover, he closed in on the firing position. Power armor was a technological marvel, but he knew that it was a finite thing and hard to repair. It made no sense to risk it. He'd take the calculated risk of a sprint from position to position, always understanding that the grenadier was up above on a raised defilade that protected him from direct fire. Explosions continued to crash around him, pummeling him the waves of the concussion up until he managed to get into what he considered a good firing position.

Ammunition was also precious to him, but that grenade launcher was playing havoc and was a real threat. He played an instinct and readied a frag grenade. Then, rolling around to the side of his cover, he hurled it further and faster than a normal human could have, arcing it so that it would drop on his foes. The troopers, having no personal experience of what an Astartes could do, had not estimated the lethal range for such with a hand grenade. The grenade went off with a thumping explosion in the firing position, and Prodigal Son didn't lose time. With a loping movement, he got into their firing position, which was a good one. The grenade launcher's previous wielder wouldn't object to the weapon being put to its original use; to fight the enemies of the Emperor. It might not be ideal in tight corridors, but it could be vital when used against entrenched opponents...