So I am currently writing up the background to my Novabella/Ministorum/Hierophant character. While I have access to all the books and Seeds of Heresy for the Novabella fluff, I have hit a bit of an impasse. My character is a benevolent, down-to-earth former seed-scribe. His village and family were killed by cultists, and he was picked up by the Inquisition. He hates the cult that did it, and takes it out on other cults that plague the Imperium. Blah, blah blah.

My problem is this: outside of doing his duty as an acolyte, I don't have a lot of motivations or goals for him. Yes he hates heretical cults (especially his nemesis one) and will do his best to eradicate them. Outside of that, what sort of goals would someone like him conceivably have? He isn't materialistic, and is essentially the priest/village leader from a village that was eradicated on a planet far away.

I thought perhaps spreading the native Creed of Novabella, but that is kind of meh in my head. What other, personal, things should my character be striving for? What do the Ministorum Priests who aren't raving lunatics really want?

Power. Or to be genuinely good people in an overly grim-dark universe. Most acolytes don't have galaxy spanning goals in mind when they join the inquisition. Half of them are drafted, a quarter are indoctrinated into imperial culture, and the others are foolish and think it will advance their station before someone influential catches on and tries to kill them.

Heck, depending upon the mission, some acolytes may just want to finish the job so they can get off of whatever horrible planet they're currently stuck on.

Characters with delusions of grandeur or galaxy spanning ideas generally should look towards either black crusade or rogue trader.

My character is a benevolent, down-to-earth former seed-scribe

Essentially, he's a priest. He'd probably look to 'get involved' with the local ministorum of wherever-he-is. I'd imagine he'd want to preserve and spread the faith in the Harvest-Father, but I don't see him standing in a cathedral with a heavy flamer....

If he's politically inclined, then trying to get himself promoted within the ecclesiarchal hierarchy might be good - after all, it'd be useful for the acolytes as well. He doesn't want to accept any parish or diocese because he doesn't want to be tied to a specific place (it'd limit his ability to help the acolytes) but some sort of ecclesiarchal rank would be helpful and be a good justification for increases in his influence score.

Some sort of messenger/ambassador/roving administrator would be perfect - the Ecclesiarchy, as well as being a religion, runs worlds, palaces, schools and wars (sort of) so must have people who do that sort of thing.

The contemporary equivalent, in the Catholic Church, is the Papal Nuncio -

https://en.wikipedia.org/wiki/Nuncio

My character is a benevolent, down-to-earth former seed-scribe

Essentially, he's a priest. He'd probably look to 'get involved' with the local ministorum of wherever-he-is. I'd imagine he'd want to preserve and spread the faith in the Harvest-Father, but I don't see him standing in a cathedral with a heavy flamer....

If he's politically inclined, then trying to get himself promoted within the ecclesiarchal hierarchy might be good - after all, it'd be useful for the acolytes as well. He doesn't want to accept any parish or diocese because he doesn't want to be tied to a specific place (it'd limit his ability to help the acolytes) but some sort of ecclesiarchal rank would be helpful and be a good justification for increases in his influence score.

Some sort of messenger/ambassador/roving administrator would be perfect - the Ecclesiarchy, as well as being a religion, runs worlds, palaces, schools and wars (sort of) so must have people who do that sort of thing.

The contemporary equivalent, in the Catholic Church, is the Papal Nuncio -

https://en.wikipedia.org/wiki/Nuncio

In 40k they're called confessors, they go out and seek to absolve people of their sins, whether through repentance or fire. They have multiple ranks for each division, its just the titles aren't quite as flashy

You could go with the faith route and make him a pilgrim on the road to the eternal salvation in the light of the Emporer (or whatever He is called on Novabella) and use his status as an Acolyte to travel from shrine to shrine in a pilgrimage. Or you could go for a more introspective role and he wants to gather knowledge of the creed from all over the universe to write a complete history of the Most Holy of Terra (pure insanity, but he might not know that).

I am well aware of the scope in DH, and am versed in the lore of the Ecclesiarchy as well. I guess the problem I have run into is giving myself some sort of "side motivation" outside of doing the Inquisitor's work and surviving. I like the idea of a pilgrim and becoming a Nuncio, as that fits well with the themes on Novabella.

Perhaps he is still beholden to the Harvester-Prelate on Novabella, and works as an ambassador for that particular bent of the Creed. Or, he does things assigned to him by his master on the side whenever possible.

What sort of organizations (secret or otherwise) would be conceivable at that rank, as well as fitting in with Dark Heresy? While I am aware the game is ran as a group of acolytes, that doesn't mean they are without connections or even a cult of their own..

A good source of inspiration maybe Galadriel from Middle Earth...

The gist being with her, when she refused the ring "if she takes the ring for herself - her righteousness (though good in her eyes aka the road to hell is pave with good intent ) will result in such heavy handiness and or abhorent action - that she does not do so. The key facet herein is "preceived good" that your character thinks he is doing - become engorss by his good deeds, force the goodness down the throats of the masses who need it (maybe thats how he feels) - again take something wholesome like "being good" and take it to the max - you might be surprised by what you end up with

Morbid

Perhaps losing his family led to more than just a hatred for cults. Perhaps a drive to help others negatively impacted by the cowardly acts of heretics and a drive to find other ways to help people protect themselves. Building orphanages and helping families reunite, teaching peasants to fight and to better identify heretical threats before they become too strong.

In 40k they're called confessors, they go out and seek to absolve people of their sins, whether through repentance or fire. They have multiple ranks for each division, its just the titles aren't quite as flashy

Not so much. Confessors are still classic Ecclesiarchy priests, just roving ones of no fixed abode.

A Nuncio is a combined administrator/ambassador/diplomat who just happens to be an ordained priest, whose job neither to bless you or burn you but to go to an area and make sure that the local ecclesiarchy has alliances and contracts in place with the local nobility/governor/etc so the priests of the diocese have food, shelter and flamer fuel.

It's a good career move for a more subtle and less "pryomaniacal psychotic" of the Ministorum....

And he can be some kind of "field theologist".

Imperial Credo has sincretic doctrine, so there must be priests who study local cults and create basic versions of incorporating local believes into Credo.

I was definitely thinking of compiling reports on the variant Imperial Cults I encounter to send back to the Harvester-Prelate of Novabella, as one way of small Influence gains. The more I think about it, the more I like the Nuncio idea. It fits well with the lore of the Ecclesiarchy on Novabella and is less "chainsword and flamer" than most Ministorum occupations.

Turn him into a crusader. He starts out going after cults of opportunity, but then as he gains reknown amongst the Ecclesiarchy, and consequently lots of influence. As a true devotee of the Emperor he never accepts greater clerical rank - everyone knows that rank is not as important as perceived spiritual charisma and influence, and his actions against heretics and schismatics have given him an impressive rep.

Eventually he can start to use his influence to go after bigger and darker cults on a grander and more sweeping scale.

How about questing for some kind of artifact?

The priest discovers from a (captured & tortured) cultist that the cult that destroyed his village was looking for clues to the location of some kind of artifact. The priest first starts to research the artifact and later decides to chase it himself when not busy on inquisitorial duties.

Easy for the GM to work some clues or NPC's in the regular campaign and for the player to occasionnaly go off to find information etc.

And it could easily lead to small confrontations with cultists seeking the same information without requiring a lot of prep time.