Originally Posted by Brother Lucian
If you remember Zahariel in the HH DA novels, the watchers in the dark was trying to influence him due to him being a psyker. They even bought the world spirit of Caliban to him when he came under the delusion that the bound Ouroboros daemon was the true worldspirit of Caliban and sought to free it. But he rejected them.
Good point about Zahariel. This might also indicate that they are not Pariahs, but something much different. If they were he wouldn't have been able to be near them.