Does a spirit need to materialize to use influence

Background count has been toned down from 4th edition. Back then, when an adept entered a background count, their magic was offset by the amount of the background count. They had to, then turn off powers that they couldn't sustain with their new power point limit. If they had 6 points of powers and entered a background count of 1, they had to turn off enough to get it under 5.

Now, background count is simply a penalty that is applied any time you use a magical thing, be it active or passive. This means that your adept that took an Enhanced Accuracy with magic is using that to boost their limit to a weapon by the rating of the Enhanced Accuracy. If you had an Enhanced Accuracy of 2 and walked into a background count of 1, you're fine. You still get a net of 1. However, if you walk into a toxic waste dump and have a background count of 3, your mana is now screwed up to the point that you're getting a -1.

It's easier to understand it like this. You have bad eyesight. You put on a pair of glasses. The glasses are the mana that's weaved around your eyes to make them see better. Normally, with an eye-glass prescription, it's made so that you get a 'bonus' to your eyesight. However, those glasses can have all sorts of things happen to them. Fog, being broken or scratched, or even having the lenses melt and shift the image and bend of the glasses. Now, you're taking a 'penalty' to your eyesight. The game is giving you an out by saying that you can turn off a passive power so that the negative mana doesn't interfere with your normal mundane skills. Ergo, you can 'take off your glasses' until such time as you get out of the area that's fogging them up.

In cases of Improved Reflexes, I would rule that you would have a -1 to your Reflexes for every background count. The contention would be what happens to your added dice. My opinion? You'd lose a die for each point of background count, down to your minimum of 1.

Let me start by saying that I don't know any official citation that gives a reason for stun being more draining than lethal damage. But I know what happened in sr4 in my group and that sheds light on a list of valid reasons why they might have done it:

In sr4, spells doing stun damage were cheaper on the caster than spells doing real damage. However, a person that is completely stunned in a combat is just as dead as a person that is really dead. Because killing a stunned target is basically a free non-combat action without cost. If not getting enough damage to be out of the fight instantly, you get modifiers. But it does not matter if it was stun or real damage. The modifiers are always the same. So:

• to stun somebody, you would prefer to do enough stun damage.
• to kill somebody, you would prefer to do enough stun damage and later kill him trivially with a knife or firearm

Going for real damage only made sense in combination with other damage sources that did lethal damage so it would add up to an amount ending the fight. A well optimized caster could take out people without such a use of combined arms however. So for a well optimized caster, using the cheaper stun powers for killing was the economically viable choice.

So my guess is that the more powerful spell (choice between stun and stunned and later killed anyway compared to always killed) was made more costly than it's lethal counterpart so people intending to kill actually use the deadly spell for this purpose.

Considering in-game justifications for the mechanics, at first glance it seems odd because killing is more powerful and should be more taxing on the caster. But one could argue that the drain actually takes it's toll from the amount of control you have to assert and killing someone outright requires little control while managing the exactly right amount to stun somebody requires a lot of control over the magical energy used.