One of my players has taken Black Priest Maccabeus alternate rank and gained "Encarta Maleficarum" talent
"Some Black Priests, in order to aid them as holy exorcists, are subjected to a secret ritual that Ordo Malleus calls the Encarta Maleficarum. During this ritual, forbidden knowledge is burned deep into their minds, shackled with wards inscribed by occult means directly into the cerebral cortex. This procedure rare and considered a radical one even by the most ardent of Daemonhunters, as the survival rate is not high and, even if successful, the recipient’s life expectancy can be seriously reduced and their sanity eroded. The Encarta Maleficarum is treated as an Elite Advance (see page 229 of Dark Heresy). Upon spending the xp to acquire it, your character disappears for 1d5 weeks, as the Black Priests put your faith and endurance to the test and inscribe burning lore into your mind. As a result of this procedure’s harmful side effects, you gain 1d5 Insanity Points and you permanently reduce your Toughness by 1d5 and your Fellowship by 1d5.
This heavy price buys fearful knowledge and armours you against the whiles of the Daemon: your character gains the Forbidden Lore (Ordo Malleus) skill and the Insanely Faithful talent. Also you gain a +10 bonus on all Tests made to resist torture and interrogation, attempts to read or control your mind and any form of possession. In addition, if an attempt to possess you does succeed, but by less than three degrees of success, the assault or intrusion is blocked by the wards within your mind—it fails and you collapse in a catatonic state for 1d10 minutes ."
I am concerned about the last part of description (bold). A player believes it applies on any psychic power which does anything with mind. I think that it applies only for some powers - Dominate, Beastmaster, Seed Mind and of course actual possession. This alternate rank is from Ordo Malleus which is for fighting deamonic things. Even rank's description says that. So, I think it does not apply for psyker thing (there are other special talents for this). Such powers as projection, suggestion, telepathy, inspire, see me not should work and the only thing Priest gets then is +10 bonus for opposed test . What do you think?