Color me interested and count me in if it's possible. I'll either make a shameless ripoff of Dio or a hebrew-themed ancient world eater marine. Also i'd like to know if playing as a moderately powerful demon or an actual daemonprince is possible.

"Angron is a lion's whelp; on prey, my son, have you grown. He crouches, lies down like a lion, like the king of the beasts; who dare rouse him?"

You are completely and utterly  disinterested in playing by the rules of actual Black Crusade tabletop game though, right? Asking just in case.