I would be some kind of ritual, which should be designed to took out the victims mental stress track and then adding shifts for consequences. The classical mindless grunt would get the extreme consequence "Enthralled" or something like this. Every time he gets an order form the wizard, he wold get an compel for this consequence.
Rulewise: The complexity of a ritual like this would be: Conviction (or perhaps discipline) of the victim + 4 + shifts to fill the mental stress track and add consequences.

Another possibility I could imagine is to use Spirit evocation to attack the thoughts of a victim using his conviction (perhaps discipline...Iīm not sure) as a defensive skill. If you deal enough stress to create consequences itīs like the above sample.

Some ideas for True Hope:

Someone with a terminal illness, who is still happy and has perspectives in his life.

Some strong religious believers, who have witnessed war, rape and other bad stuff, but still believe in the general goodness of mankind.

The city of Las Vegas or similiar places should be bad mojo for Skavis. Although everybody knows that in the end the bank will win, they are hoping for the big prize. Here I wouldnīt say itīs true spiritual hope but a lot of people with a lot of hope at one place could disturb a Skavis WCV.

@Richard: Yes youīre totally right about this forum. In german forums you normally have the same problems with people, who threat you like crap. Some people seem to think they donīt have to be polite, when they are more or less anonymous. This reflects a bad light on those people: They are only polite, if it may reprisals if they arenīt. Here nearly all posters are friendly, constructive and helpful.

So thank you all guys for the discussion. I now have some new points of view and I am sure I and the ectomancer player will work something out regarding the fifth law.

@Umbralux: Yes of course this would be the ideal solution, if there wouldnīt be a lot of grey areas. From my point of view it isnīt a clear choice, neither for the player nor the GM. I agree that some dice rolls, which decide if you are morally rotten or not are not very elegant. My houserule was more or less some kind of brainstorming. It bothers me a little bit that there is no inbetween for lawbreaking.

For example:

I would like to simulate this rulewise: There are things that are not really lawbreaking according to the letter of the law, but the should have a small impact on the soul of the wizard.

@Richard Chilton: Yes the white council doesnīt bother. But how cruel is it to force a feeling, intelligent being to fullfill you every wish. When you use magic for this, it should be some kind of "lesser lawbreaking", donīt you think?

Very interesting discussion! It seems to me, that especially concerning ghosts, the opinions are very varied.

Personally the way I figure it is that with a zombie you are using a dead body. That dead body is a link to the person who used to be inhabiting it.

Additionally Quantus is right about necromantic energy being different from normal magic.

I think for me this is the main argument against creating zombies. The body must be a really strong link to the soul of the former owner of the body. So by giving the body false life, you are disturbing the dead. And there is the lawbreaking. Since animals have no souls (?) it might be not good manners to raise them, but you donīt play around with some souls.

The matter on ghosts is a lot more complicated. If it has no soul it seems to be no problem to force them to do something with magic. Of course, to state it again, itīs morally really problematic to do so, but form the point of view of the white council it shouldnīt be such a big deal. (When Harry enthralls a fae Morgan is not happy but canīt do anything about it: @Lanodantheon: I am reading the books in the moment but my gaming group donīt know them :-) In the moment  I am reading White Night so Dead Beat is done :-))  But still I have the feeling that raising animal zombies and forcing ghosts into fighting frenzies SHOULD leave a small stain on the wizards soul. Not quite enough for a lawbreaking but still.

I have thought about it and have come up with some kind of houserule. Maybe you people are interested in it.

Example 1: Wizard A is creating a big ugly zombie to beat up an enemy of him. He now gets his lawbreaking stunt and thats it, because there is no leeway.

Example 2: Wizard B is forcing a ghost to beat up an enemy of him. Since the ghost has no soul itīs not really a lawbreaking, but you also enthrall it and perhaps a part of the spell is using a tiny bit of death magic. As a GM I would state that he is about to walk a darker path and therefore his soul maybe stained a little bit. To simulate this in game terms: The GM rolls an attack with a  desired strength. Lets say the GM thinks this is a minor staining and he sets a strength of 4. He rolls a 2 and therefore the attack has got as power of 6. The wizard may use his conviction (because he might believe it was necessary to send the ghost and for the greater good and so on) and his roll results in a 4. Therefore he got two shifts form the attack. This shifts are used to open up the stress track necromancy (or vice versa for another not quite lawbreaking). Perhaps it could be of the same length as the mental stress track, but it wonīt clear as fast. Maybe you may roll conviction against stress +2 or something to remove one point of stress every minor milestone. When the stress track is full you get your lawbreaking stunt.

This seems to be a bit complicated, I know. But I donīt like to see things only black and white. Perhaps the white council does this a lot. But for roleplaying reasons it might be more interesting to see someone fight with his own conscience, after he has done something very questionable.

A tall and slender tower, inhabited by a fae sorceress, who collects Humans as servants and playthings.
Some lonely coniferous forest with thick undergrowth and a permanently creepy howling wind between the branches.
A beautiful meadow full of flowers and some pixies, who are prancing around.

Maybe you think a little bit too much about it. But this is at least a lot better then not thinking about the powerlevel. My limited experience with the Dresden files rpg shows that it is not so important how big the powerlevel of the characters is, because there is always a bigger fish to challenge them without stretching the universe too much.
In my opinion it is a little bit more interesting how much experience the players of your group have concerning the Dresdenverse and roleplaying in general. If the are unexperienced it might be too much to start with a lot of power right form the beginning of a campaign. They might end up using only part of their abilities "effective" and maybe canīt work as a team to substitute each others weaknesses.