>>714361949
Oh you might be surprised. Posting a tumblr link only to illustrate:
https://askrobouteguilliman40k.tumblr.com/post/750872359200817152/can-you-blame-them-when-this-is-his-official

Similar stuff out there for Mechanicus types into tubes too.

>>714368840
No books where he's a main character, but he's a background antagonist in "Severed" by Nate Crowley and he fights Black Templars in the short story “Dishonoured” by Ray Harrison