hollow saddle
So I don't know, TBF, if this would be better than what we have now or not, but I wonder if having Evil's voice get less stable whenever she gets the Demon toggle - so she literally becomes the Abber Demon when she has the horns - would be a feasible idea.
On one hand, I think this could work, because she has 2 toggles - demon and cat - so the demon toggle wouldn't be seen as frequently, making it still a special occurance, but on the other hand I feel like it might be too much - part of the charm of the Abber Demon is its scarcity and unpredictability. So I'm on the fence about my own idea (wow, such confidence, I know) but it's an idea, at least. 