Well, as the title implies, can you actually sustain a pushed power? I havent really seen anything specific about it, its all been general sustaining..

When we did it, some of the players found it a bit much so we ended up saying that we could but there would be a psychic phenomona roll each round with all the modifiers as I had on my first roll..

And while we are on the psychic powers subject, how high can a tzeentch psyker get his psy rating? i mean, are mark of tzeentch and warpsmith something that gets added in the moment you get them, meaning, if you already had raised you psy rating to 10, you could theoretically get 13, but if you get them early, you will only be able to get to 10…

I have searched for these answers here, but havent really found any real answer, . Has anyone sent any of these off as rule question to the powers that be?

Yes, you can sustain a pushed power, and it is sustained at the psy rating it was cast with. Just like you can sustain a fettered one. It's a pretty common tactic for things such as telekinetic armor or warptime to simply push it once and then maintain it at a higher rating.

However, do keep in mind that sustaining multiple powers lowers the psy rating of ALL sustained powers by 1 for each power. Likewise, even instant effect powers have their psy rating decreased while a power is sustained. Likewise, you increase all your psychic phenomena rolls when sustaining multiple powers, so it's not a risk free endeavor.

As for psy rating, it is added at the moment, however the maximum psy rating one may have is most likely 10. While the blurb on psy rating could be read to suggest otherwise, it does list the maximum psy rating as 10.It's certainly the ruling I would make. A Tzeentchian sorcerer can already push far beyond that with clever use of Boon of Tzeentch and other powers, and doesn't need further help.

As we're in the matter of sustaining, I'd like to solve something: do I have to reduce the PR of my powers when I'm sustaining one and casting another: i.e. I'm sustaining Telekinetic Armor and them cast Doombolt. Are they both at normal PR used as casting or reduced?

The way our group has dealt with the problem of maintaining sustained powers is via fatigue.

Basically, we've ruled that every minute you sustain a power at Push level you gain a fatigue level, every 2 minutes you sustain a power at Unfettered you take a Willpower test that increases in difficulty by 10 every time (So first test is at +0, 2nd at -10 etc) with failure incurring a fatigue level, and powers at Fettered you last some number of hours before having to take a similar willpower test.

Sustaining multiple powers divide the time by how many powers you use.

This way it limits psykers from simply sustaining big powers all day after pushing once with sacrifice to prevent any problems to them.

Also, based on my reading of the rules, sustained powers and active powers do not interact with reduced PR (yes, I know the table has the reduce +1 PR per power). Going by the rules text under Sustaining Psychic Powers

"Sustaining multiple powers is more difficult and more
tiring. Any character attempting to sustain two or more
powers at once must spend the longest action from the
Sustain Requirements of all the powers being sustained,
and reduces the effective Psy Rating for each power by
the number of powers being sustained."

Based on this, our groups reading is that you get the first sustained power 'free' (apart from increased chance of Perils) but as soon as you sustain another power, you reduce the PR of both by 2.

Nimas said:

You are correct in that, but remember that if you sustain a power and then cast another non-sustainable one, both are also reduced. We had some discussion on how to do this and we use -1PR for both powers (as you are sustaining only one power) till the psyker's next round.

ShadowRay said:

I'm pretty sure that's not how it works. Sustaining one power does nothing to affect anything apart from a little harder phenomena tests, "requiring minimum effort" I believe the book says. You only start to suffer PR penalties when you've got multiple powers sustained at the same time .

Examples:

You sustain 1 power every turn with a free action as a csm. All power usage is as normal, as it requires minimal effort, but all your phenomena tests are at +10.

You sustain 2 powers every turn with a free action as a csm. All power usage is at -2 PR [2 powers x -1], as it's "more difficult and more tiring" to sustain multiple powers, and phenomena tests are at +10.