I have a player in my campaign that plays a Moritat death cult assassin.

I do not feel that any of the back grounds presented fits. I think this is one of the core 40k back grounds, and also quite common among inquisitors acolytes. So maybe add a "Death Cult" back ground?

It could look something like this:

Starting skills: Common lore (death cults), Stealth, Awareness, Parry

Starting talents: Weapon training (some melee weapon)

Starting equipment: Body glove, some melee weapon

Back ground bonus: no good idea yet, anyone?

Bonus aptitude: Offence

Recommended roles: Assassin, Desperado, Warrior

Outcast?

Outcast really feels more like the Scum option than anything. If I had to make a Death Cultist under the current system without adding things, I guess I'd go with Ministorum. Death Cults are followers of the Imperial Creed, generally. In a very warped way anyway.

An Officio Assassinorum Background would be nice - it would be very tailored to the assassin though...

Well, they need things to put in Supplements.

An Officio Assassinorum Background would be nice - it would be very tailored to the assassin though...

Aren't Officio Assassins a little out of the scope of Dark Heresy? They're not the kinds to hang around in an Inquisitor's retinue solving crimes, they're combat tools used to, well, assassinate.

If an Inquisitor is included as elite package, I think an aspirant from the officio might as well join the acolytes to gain some killing experience in the field.

Eh, I guess I could see it, but it feels outside of how the Officio operates. Vindicares being included in Ascension was a horrible move, in my opinion. Temple Assassins work much better in the new reinforcements system.

But an officio background would offer different kind of assassins a way to be seconded as acolytes to get experience before they get their final rank.

But an officio background would offer different kind of assassins a way to be seconded as acolytes to get experience before they get their final rank.

That just doesn't really work with the lore. Officio recruits are typically schola progenium or feral world kids who are scooped up for one reason or another and honed into weapons while they grow up. Its not really in the canon for them to accept outside people and flip them into bonafide temple assassins. As a result, a "role", "career", "path", "advance", or whatever you want to call it really doesn't make sense as they are trained inside the temple until they are ready, then used as seen fit. At best maybe a PC could be an escaped, abandoned, forgotten, etc. aspirant that the inquisitor picked up, but by that point it still wouldn't make sense for them to have an advancement path labelled "officio". I know this might seem fun-killing, but it has more to do with the lore than what you want to achieve. I'm all for more character gen. options, just not ones that don't make sense in-universe.