1. Twilight Gate (TH) - This turns your early-resourced Faceless Abductors, Many-Angled Things, or a plethora of out-of-faction options into pseudo-events, and allows you to accelerate a main domain at the same time.
2. Frozen Time (TKatG) - 2 cost to blank pretty much any card is just very good.
3. Doppelganger (TWB) - This character basically allows you to act like you are running x6 of your best characters, except you have flexibility to choose which character you want to copy. Two Faceless Abductors? Two Many-Angled Things?!
4. Faceless Abductor (TOotST) - It is a decent character in its own right, with good icons, but when you can target an opponent's character at a story, this becomes a great tool for swinging stories your way, or forcing your opponent to sit on his hands.
5. Many-angled Thing (TGS) - Great economy! You net a character and your opponent loses one and all the resources they paid for it. Decent icons too.
6. Pushed into the Beyond (TbtA) - A similar effect to Faceless Abductor, but since it's an event it can be even more impactful. A smart opponent would always think you could play this at any moment.
7. Rite of the Silver Gate (TKatG) - There aren't many things that can take out an AO with one hit, but this can.
8. Stalking Hound (PT) - A great "touche" effect just when your opponent thinks he's being clever. Expensive if you need to pay for him, but otherwise a good deal.
9. Professor Nathaniel Peaslee (TKatG) - One of the cheapest and easiest ways to take control of a character. Sure, there's the risk that you play hot potato in a mirror-match, but it's too good otherwise.
10. Lost Oracle (TKatG) - With a modicum of arcane and other discard effects, you can really slow down a rush deck.
Honorable mentions (probably too many smh):
- Glaaki (AoA) - This AO can be a real head-ache for your opponent. He can deal with pretty much any character on the board, even AOs, by driving them insane and making them ripe for wounding. Probably one of the best AOs, but without resource ramping AOs aren't much of a thing right now.
- Interstellar Migration (TkatG) - Probably the representative card of the infamous mill deck. Very weak on its own, but with other discard effects and some yithians, it's hard to combat.
- Things in the Ground (SoA) - Last but not least is a card that, while it may affect how you build your deck, is one of the easiest and cheapest ways to get large beef into play early in the game.A Single Glimpse (Core) - This is probably one of the best of the sacrifice events for Yog. With enough other board control, you can make your opponent have a very difficult choice.
- Calling Down the Ancients (SoA) - similar to A Single Glimpse, this allows you to target a character, but places more limitations on your choice. Running it with skill reduction effects works really well.
- Eltdown Shards (***) - This is probably my favorite tome as it gives you a better chance of triggering the condition, and giving you a good defender, which could mean a solid two-card advantage each turn. When you combine it with conspiracies like The Painted Corpse (MoE), The Grand Design (TbtA), Combing the Archives (LR), or From the First Degree to the Last (TbtA), it becomes absolute devastation to your opponent's hand and allows you to ready multiple characters for defense.
- Journey to the Other Side (Core) - Allows you to determine that your draw for the next turn, and gets you a card at the same time. This is a good example of Yog's theme of simultaneous deck/discard/hand manipulation or filtering.
- All are One (TSC) - A similar effect to Journey to the Other Side, this one searches less but puts one in your discard, Yog's backyard playground.
- Cannibal Ghast (Core) - A great defender when you need to bide your time and build up.
- The Sleepwalker (TAD) - Similar to Agency's Government Exorcist (TSotS), this perhaps gives you just as much choice in targets, and she is immune to insanity due to her terror icon.
- The Large Man (TSS) - This large dude packs a powerful effect. Any event back to your hand. Lots of possibilities with him although he is a little expensive and vulnerable.