If the 5th Dantek is what you get when you stack up a PDF Regiment against some of the more notable Guard regulars, then Harlan Nyall is what you get when you stack up an Engineer from the ass end of an Asteroid Belt against the Tech Priests of the Adeptus Mechanicus.

Just as there are Tech Priests Imperium wide that tend to the little agri-communities and long haul shipping outposts, so there are Tech Priests that tend to the heavy machinery and void ships that ply the Dantek belt, providing raw materials for the production of the marvels in the far more famous Forge worlds.

Most, and I mean the vast majority, mistake him for a servitor when they first meet Harlan. It's alright, he's used to it. From the pale depilated skin to the sizable industrial drill that takes up the majority of his muscular back and right shoulder, he does not resembled the red robed figure that the title usually conjures.

But aspiring Tech Priests don't get to pick the valuables treasures that are grafted into their flesh, at least not the initiates, and in the Dantek Belt a shoulder mounted mining drill is very useful in day to day labor. As is the respiratory filter that protects him from the hazardous particulate it kicks up that would otherwise ruin his lungs over time.

Of course this was all before the Tithe, before the PDF, and before the 5th recognized that a hyper-dense adamantine mining bit can breach Ork Rocks just as easily as any of the other kinds floating around their home belt.

That's not to say Harlan is just a big walking mining platfom. His surly disposition, experience as a deck hand on Void Ships and his down to earth (For a Tech Priest) demeanor have endeared him to those that survived their last deployment.