When I am designing new monsters or a Great Old One, often I run through several ideas for what, exactly, its special ability or spellbook ought to be. Sometimes after a test I reject an ability because it slows down the game, or because it is too powerful in conjunction with another spellbook.
I don’t throw away the “orphan” abilities. Instead, I save them in a special file and go back to them periodically when looking for ideas. Sometimes they get resurrected, when they fit the theme appropriately, or I’ve found a way to fit them into the game. I have probably about a hundred of these lurking around, waiting in case of future needs. So someday you may see one of these so-far-unused powers re-appear again:
Reverse Battle Rolls – 4 & 5 are Kills and 6 is a Pain. The main reason this was never used was simply because I never had a Great Old One for which this fit the theme appropriately. Theme is mucho important to me.
Movement is unlimited – i.e., when you take any other action, you can also take a Movement action. I never ended up using this because it seemed to water down the “Battle is unlimited” capacity that you gain at 6 spellbooks. Also, it slowed down the game, because players, after taking an action, would then always stop, and peruse the board carefully, looking to see if they wanted to Move. And then they never did.
When you capture a Cultist, immediately sacrifice him, return him to his owner’s Pool, and gain 1 Power. I dumped this ability because a player walked into another player’s home area and then proceeded to capture every single one of his Cultists, powering his feeding Frenzy with the Power he stole. Ouch that smarted!