One of my players is trying to convince to allow him to create some tribalistic "tech-shama" as a techpriest with a feral homeworld, his argument is a lopst ark mechanicus form the golden age of technology that crashed in hte planet with no hope of being able to leave the planet. The feral inhabitants adopted Ark Mechanicus and the Omnissiah into their tribal beliefs along with techpriesthood practices with some changes of course (for example dressing in robes made of xeno hides and using tribal percusion in their incantations). It's been about 10 milleniums since the ark mechanicus crashed and the planet was rediscovered some centuries ago.
I kind of like that plotline, so now the question is this: How should be the background of such character? and in gameplay terms what should be the correct modifiers?
I've already thought about the planet being half feral, half forge because of the way to live in an Ark Mechanicus and the tribal way to gather resources.
So what should i do now to give life to this character?