Can you elaborate, please?
The problem is that evocation is the most powerful (or tied for most powerful with incite emotion) offensive ability plus is the second most powerful defensive ability (is behind enchanted items). Which means that it's worth 3 points for those abilities alone. Adding the ability of evocation to do 'other stuff' means that you get both very powerful offensive and defensive abilities, plus whatever other stuff you add to it.
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Now, how to get the effect you want? Sounds like you might want something like incite emotion or Sanctaphrax's incite effect power, both of which are powers more geared to doing 'other stuff' than evocation is.
Another option is to work out some sort of (refresh costing) expansion of evocation, which allows you to do 'other stuff'
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Here are two of the ideas I've had for allowing evocation to do other stuff:
They are taken from
this thread where there's a bit more depth of discussion.
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idea 1:
While evocation is technically capable of many tasks, many of them require considerably more skill, practice, and luck than most wizards put into it.
So what are these 'other' uses of evocation?
Many skill rolls can be outright replaced by evocations, examples include moving (force jumps, 'tactical' hops through the nevernever, etc), very fine manipulation of objects (lockpicking, eavesdropping, fine craftsmanship, etc), illusions of considerable complexity, etc
In general, the power of the evocation will act as a roll of the appropriate skill.
You can gain access to the 'other uses' of evocation in the following ways:
1
Spend a fate point, to get access to the ability for a single use.
2
spend a point of refresh of a permanent expansion of your evocations to cover one trapping of a skill.
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idea 2:
Basic evocation includes one skill trapping replacement for 'free', Harry's is movement, Molly's is veils, other wizards might have other basic abilities. For example, if you want to have (some) knowledge of the ways, then maybe you'll take the navigation trapping of driving.
This means that the RAW can stand almost exactly as written, with most wizards being assumed to take veils as their default.
This removes spirit as the most equal element, puts slight hedge on free veils, explains why Harry doesn't do them until several books in, and hedges in other skill trapping replacements of evocation.
It's not really perfect, but does seem to solve some slightly irritating issues, (somewhat) hedge in free expansion of wizard power, and is easy.
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Both of those ideas have potential problems, but both do attempt to draw a line around how you get evocation to do 'other stuff' and what 'other stuff' you can and can't do. Otherwise it's just 'whatever you can talk the GM into' which is a pretty bad idea, especially with evocation being as powerful as it is already.