I'm not sure the Sisters of Silence even exist anymore after the Horus Heresy. There are no references to them existing in the 41st millennium in any source. Since pariahs are so rare and more psykers are being born every day, I think what happened is that the Sisters of Silence as an organization were disbanded after the Heresy, and the remnants were reorganized into the guards that man the Black Ships, and they started recruiting from men as well in order to keep their numbers up (or used to train into Culexus Assassins). It doesn't make sense to recruit from a specific and very rare type of person, and then exclude half of those potential recruits because they aren't women. The Ecclesiarchy is forced by law to recruit from only women for the Adepta Sororitas ever since the Age of Apostasy (since they are forbidden to have men under arms, according to the law as-written) and the Space Marines are forced to recruit from only men because the gene-seed implants simply don't work on women, for whatever reason.

To be honest, I don't like the idea of the Sisters of Silence to begin with. The vow of silence seems to be tactically unsound. They can't use a vox, to start, and they can't communicate with anyone who doesn't know their sign language, which makes them a serious liability in an investigative mission. They'd also stick out like a sore thumb even more prominently than a Guardsman with a grenade launcher. And lastly, their armor and topknots are ugly.

Never said it was a Sisters of Silence character ;)
Just using the rules from the playermade thing. It has rules for non-Sisters as well :)

http://manuel.rifault.free.fr/Public/JDR/Dark%20Heresy/Sisters%20of%20Silence.pdf

One of my PCs was a Null, a young female adept that was born and raised on an Ecclesiastic world and pressed into service in the Adeptus Ministorum when it was discovered that she had an affinity for large number sequences. Eventually she was assigned as a ministorum liaison for a group of acolytes working under a fledgling inquisitor and he was so impressed with her efficiency and skills that he took her on as a permanent addition to his team. The position the adept had been assigned meant that she never came into contact with any psykers or any psy-reactive materials, so her Null powers were never detected. Though she often had difficulty telling one end of a lasgun from the other, her deductive and reasoning skills were second to none, and the tech-preist quickly became endeared towards here, though his flesh crawled when he was near her, he just assumed that was a quirk of his weak flesh, and so treat her no different than any of the other acolytes in the cell. The rest of the group kept her at arms length, but assumed the strange aura around her was due the sheer amount of time she spent with the tech-preist.  The techie eventually died, and the cold reception she was given by the rest of the cell lead to the adept requesting a transfer off frontline duties and so she was retired. Unfortunately, her Null powers were never discovered by the cell or the inquisitor, though the mission reports handed in by the cell highlighted some strange phenomenon that seemed to center around her, but before I could write in some rival inquisitors or general plot hooks related to her, my player tired of her character being basically shunned by the rest of the group and made a new character, keeping the Null in reserve in case of emergencies XD 

You must also remember that stats are baseline for interaction; paying a beer to a scum in a tavern could give the character a +10 on its fellowship test, having saved a child in a grox rush could easily give +10 or even +20 to the test when the null is interacting with the young's parents or even the kid himself.

Bonuses and maluses are there to represent the particularities of a situation while the statline of the characters represents his hability to do in any condition. I think that a null is, yes, hindered by its nature, but a null that knows how to speak and act correctly can still be quite inspiring.

Playing as one was a very enjoyable experience….

His name was Dar from the planet of Dusk…took the assassin tree going along the dual melee tree. He had no social grace or skill and was always very to the point (no pun intented). In the course of his career he had saved everyone in the party at least once, usually played the part of the body guard.

One of the very epic moments was when a former PC was used to be a vessel for a demon. It was in the process of becoming a demon prince and to slow it down and give the team a chance Dar lept onto its back, and then rode/grappled the demon/PC like a rodeo bull. Yes Dar ended up living through that…

The major drawbacks are not really being able to interact in the social aspect AT ALL

Also the party psyker having to fight the urge to be in confrontation with Dar whenever we are near each other.

All in all by far one of my favorite PCs I have built and played.

Boss Gitsmasha said:

Right now there is a lot of back and forth on the topic.

For my group we take it that they only really exisit and help to maintain psykers on the black ships that still travel the void