1. Apeirophobia (NN) - This card is so good it needed to be errata'ed, and it's still almost as good. Painful Reflection (TWC) is another equally devious variant of this.
2. Feathery Watchers (DD) - Like the Agency's Government Exorcist (TSotS), this allows you to choose a problematic character that can't participate; it's better in that it can be almost any character, but it can't target an AO.
3. Hamu XX 15:14 (SoK) - Very good card recursion, which is just as good as drawing two cards from the deck. If you get two Hamus, you can recur the same cards over and over.
4. Infernal Obsession (TAD) - I'll take that, please. Very little to argue with here, except its cost.
5. Stygian Eye (IT) - And look at that! When compared to Infernal Obsession, it trades 1 cost for a somewhat less permanent effect, unless you take control of a character with a terror icon or willpower. And even then it goes back into your deck for later.
6. The Seventy Steps (IMoD) - The bane of rush decks. A first turn Steps can slow your opponent to a crawl while you set up. This dominated the meta in 2011 in conjunction with the now-banned Endless Interrogation (TTftS) and Magah Bird (JtUK) (banned because of this actually).
7. Deranged Diva (WoP) - While vulnerable to destruction, this single two cost character can disrupt tempo very well since with each use it's setting your opponent's character back two turns.
8. Power Drain (Core) - This card can unravel your opponent's critical effects. A smart player wouldn't do anything stupid if a Hastur deck has a 2-domain open.
9. Scotophobia (Core) - Great for surprises at a story to drive your opponent's characters insane.
10. The Cavern of Flame (ItDoN) - This is one of the best story control cards in the game. You have to plan your deckbuilding around it a little, but having Guardian Pillar (SftSK) and The Seventy Steps (IMoD) for their dreamlands trait certainly won't make your deck worse.
- Victoria Glasser (Core) - A cheap villainess, whose enters-play effect can usually find a target. Using her with Victoria's Protege (SftSK) and maybe The Thing Behind You (TPtY)
can potentially get you a lot of mileage out of her.
- Jiang Shi (CotJE) - A great card that your opponent must play around.
- Crazed Arsonist (WitD) - Excellent repeatable location control.
- Dangerous Inmate (SfW) - A machine gun against weenies.
- Performance Artist (Core) - For 1 cost, getting this early game can be very annoying for your opponent's plans.
- Ward Phillips (SotD) - cancelling character abilities can be very helpful, to say the least.
- Shrieking Byakhee (CoC) - a great representative byakhee, this one lets you get out another byakhee for only 2 cost, so you can pull out Moonbound Byakhee (TGS) to give your servitors terror, or Obscene Byakhee (SoM) to discard an opponent's card.
- Hastur (TSC) - while not as fabulous as other AOs at the same cost, he is pretty much the only reliable, repeatable way to remove willpower from characters.