You know you can edit posts right?

There are a few units that have listed in their special rules a rule which is appended with (_____ only), meaning only that model gets the benefit but the unit still has it. I imagine this is a similar situation. When an IC joins a unit it forms one unit, their Psyker rule is added to the list of SRs the unit has but only the specific model gets access to it. A unit with a Psyker does have the Psyker rule in it, but only the model with it gains the benefit of it. The Condemnor shot rule states that units with the rule take a Perils test, not models. So a unit with a Psyker would have to take the test. It is poorly worded, I wouldn't blame anyone for rolling a dice to decide it each game.