A few players have requested that I make the level of affected enemies scale up much higher than the vanilla values, since they use mods that increase the level of enemy NPCs. I did so in the last update, but I wasn't really satisfied with that, so I gave it a bit more thought.
One of the things I've tried to do with this mod is make the spells scale up so that a skilled mage will have a full arsenal of useful spells at his or her command. That means I sometimes have to get creative with duplicate spells that are merely a higher magnitude (as I did with the *skin spell in Alteration). With that in mind, I considered making Fear, Fury, Calm, and Courage scale up so that Illusion skill automatically increases the level of enemy affected, the perks Hypnotic Gaze, Aspect of Terror, and Rage get replaced with 3 new perks that increase the area, duration, and magnitude of these spells, and replace the duplicates (Frenzy, Rally, Pacify, and Rout) with some lore-friendly spells from the previous games. Ideas include: Night Eye (already in the game as a racial ability for khajiit, but this has traditional been available as an illusion spell in TES games), Sanctuary (since there isn't a "dodge" skill anymore, I was thinking this could be based on the "Become Ethereal" dragon shout), Silence (to make it more relevant to Skyrim, this could silence enemies from shouting instead of casting as it did in previous game?), Blind (this exists in Skyrim - notably, the Falmer are partially blind, but I'm not sure how effective it is since they still seem perfectly capable of shooting me with a bow!), or Charm Animal (makes nearby animals fight for you, much like to the Spriggan ability.) I planned to leave the master level spells alone since they are ritual spells (aside from raising the level of enemy they can affect).
But... I have not spent a lot of time PLAYING as an Illusion mage. I am not sure what numbers would make the spells feel "balanced." I considered making the affected enemy levels much higher (so even players with enemies modded to higher levels can reliably use illusion spells) but reducing the duration down to 10 seconds, and then scaling up from there to keep it reasonable. I mean, casting vanilla "Frenzy" that makes enemies within 15 feet fight each other for a whole minute seems pretty powerful... but then I haven't played that way, myself. I could be totally off.
This is where you guys come in. What are your thoughts and suggestions? Am I even on the right track? Any advice from experienced Illusionists would be greatly appreciated!