If you want to look for further inspiration, check out :
GBHL's "Rules We Like to See: Main Rulebook"Like it should be for some of the other spells (Sap Will: OP), there needs to be a risk or a trade-off if they are to remain as they are. I proposed the heretical "-1 courage", but it is hard to justify -1 courage unless the fluff of the spell was changed.
The final change I proposed was splitting Fury into two spells, something like:
- Fury: As in the rulebook but without the courage buff
- Frenzy: The courage buff
This solves a lot of problems right away. If Fury still ends up being too good, then you can add a further layer of change like the OP has mentioned.
+2 courage is effectively immune to courage. 2d6+5 is pretty easy to get 10 with. Not a big enough difference to nerf it any if that were the only change.
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- Wild
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