I dont know if this has been mentioned before, probably, but in any case the latest Arbites class gave me an idea.
How about a adeptus mechanicus tech priest and a servitor with the same dynamic as Arbites and the cybermastiff.
A lot of room for funny dialog dynamic between those two and not to mention plenty of combat mechanics and very interesting weaponry.
My vision is this techpriest being very pushy and demanding towards this servitor, no remorse, almost damning it for the failurs happening in combat while this servitor will reply with affirmative action, trying it’s very best, at the same time having this doomed outlook (personality) on things but somehow manage to stay alive through all kinds of hell that are thrown at it and us (players).
Just my ten cents