Quick GM query, I'm curious how others would handle this situation. I've already got down how to dealt with it in my own way which I will reserve for a bit so this is more a "how would you do it?" I'm curious.

Situation: The proverbial waste has hit the bladed rotating proverbial. Psyker is wanting a distraction to buy time and asks the GM about intentionally triggering a phenomenon/peril in the hopes its flashy enough to get away. (Don't ask, it's like getting an answer from Tzeentch that makes sense)

How would you play that? Push a random power as normal and do it that way with it as a side perk, roll to manifest as if it were a specific power etc?

Additionally would you be harsh on them for risking the warp or generous for trying to tame it?

I would make him roll 3 times without knowing, and choosing the most fitting (worse, funny, etc.) in the hope that he'll think twice next time without scrapping the fun of the sequence.

I'd personally just tell him to push a power - he'll be getting some phenomena, and a power as a side perk.

Anyway, any player that can't think of a way to use one of his existing powers to cause a diversion is either kinda dumb or horribly failed in his choice of powers: I mean, you don't have anything that can set things on fire, bring down a ceiling or two (when pushed), or mind-control people? Seriously?

If you really want to adhere to the spirit of the thing though, let him roll on the Phenomena table and modify the result by his Infamy score - but have him gain 1d5 Corruption points is he does!

I'm always happy to roll on the perils table as GM. I'd say let him push and auto select perils for a standard roll.

I do run a "warp churn" house rule where every roll on the charts raises everyone's rolls on the chart by +5/+10 cumulative.

I'd personally just tell him to push a power - he'll be getting some phenomena, and a power as a side perk.

Anyway, any player that can't think of a way to use one of his existing powers to cause a diversion is either kinda dumb or horribly failed in his choice of powers: I mean, you don't have anything that can set things on fire, bring down a ceiling or two (when pushed), or mind-control people? Seriously?

If you really want to adhere to the spirit of the thing though, let him roll on the Phenomena table and modify the result by his Infamy score - but have him gain 1d5 Corruption points is he does!

As I experienced and discussed with others, Black Crusade really let psykers to be powerful...odd way to use the miss-use of the warp and hope for a favourable phenomena to happen...

Yeah it is very odd why they wanted to. I believe looking at their stat line few of their powers seemed to have the practical use for a major distraction hence warp phenomenon is arguably more flashy I think but I'm all for the line of:

"You can do it but there may be consequences."

So it's all good in the end...

Pretty much my default reply to anything in Black Crusade.

Sometimes the consequences are even positive!