[@Jbcool] Dread magi, a nickname for a chaos worshipping magos formerly of the adeptus mechanicus. (Or still in it if stealthy.)

The plan was that since it's a hulk, they are often made up of many different vessels. My character would have been a crewmember of one such vessel which somehow ended up as part of the hulk a long time ago. Or not too long ago, hulks tend to go through the warp from time to time, so details vary, even aboard the hulk.

So begins as crewman, BOOM accident, confused. Finds weird thing, explores, unknowingly falls to the allure of Tzeentsch, BAM dread magi! Or just a heretic.
This is just the idea, i'll of course make it proper before submitting it.