Counterbalance,
Crystal Ball,
Bolas's Citadel,
Sensei's Divining Top,
Sorin, Grim Nemesis,
Twilight Prophet,
Duskmantle Seer,
Liliana Vess,
God-Eternal Kefnet,
Watcher for Tomorrow,
Cavalier of Gales,
Brainstorm,
Charming Prince
Crystal Ball is a useful little artifact because it’s one of the few artifacts in Magic that scrys for more than one. One of things with this deck is that scrying for one doesn’t really get you anywhere since the majority of the time, you know what the top card of your library is. So being able to scry for more than one is extremely useful so that the deck can dig deeper and deeper and set you up.
Sensei's Divining Top is pretty much a staple in any EDH deck but here it does a lot of work and synergy for you by giving you fluid control with what’s on top and when. Combine with Crystal Ball and you can dig through the top 5 cards a turn to find the best possible options.
Brainstorm lets you stack the deck while still netting a card. This means you can trigger a miracle off the cast if you know the miracle's on top, or stack the deck to put a miracle on top you can the cast later. It's also instant speed with grants you some manipulation with Counterbalance. All around a useful 1 cmc instant for the deck.
Sorin, Grim Nemesis, Twilight Prophet and Duskmantle Seer are some of the main ways this deck does actual considerable damage to opponents. The Prophet and the Seer will trigger on your upkeep (usually you’ve already stacked the top card so you know it’s a decent CMC cost) and then you’ll add the card to your hand. Use Aminatou’s +1 to stack the decent CMC cost card back on top, then you can + Sorin to reveal it again. With a 5 cmc card you can do 10 damage a turn to each opponent which is pretty good.
I cannot say enough about how Counterbalance cracked this deck wide open. One of the most basic uses of this enchantment is to lock out other commanders from ever hitting the board. Using Aminatou’s + ability, you can just stack the deck with a card that has equal CMC to one, two, or sometimes all three of the other commanders on the board. It’s a little bit of a mind game too. Who knows what you might have put on top of the deck? Could be a 4 CMC, a 5? And if your opponents all sit down with commanders that cost relatively the same, you can quickly find it and try to keep them locked out for as long as possible. It also pairs well with Enlightened Tutor and Mystical Tutor as an immediate counter to a spell by letting you fetch something (artifact, enchantment, instant, or sorcery) to put on top of your deck and then letting you resolve the Counterbalance trigger. It pairs with Sensei’s, Crystal Ball and so many other cards in the deck to be a lock out and board stall while you develop. 10/10 would recommend.
Watcher for Tomorrow is Hideaway on a creature and I can't figure out why no one is going gaga over this. It also gives you the card when it leaves play, not when it dies. It's blinkable, recurrable, and lets you filter through the top of your deck pretty quickly. I'm obsessed with this little nugget.
Charming Prince is another card that does double duty in this deck for how cheap he costs. ETB to scry 2 that's blinkable its easily abused in the deck but the fact you can also blink him to blink something else can set up some pretty interesting chain reactions with other ETB creatures. He could definitely come rescue me from a hightower any day.
God-Eternal Kefnet is a pretty bomb card. Copying the spell you draw as you reveal it (which you probably already know what it is) and casting the copy for 2 less is great. And he returns 3rd down from your library when dies or is exiled so he's got his own built in recursion?? Oh, and did I mention he goes infinite turns with Aminatou and Nexus of Fate or Temporal Mastery? He's powerful and a win-con rolled into one.
Bolas's Citadel is part of a win-con but for now its very useful to look at the top card of your library at anytime. And pay life to cast it. You basically netted 20-30 mana off Bola's Citadel if you're willing to pay that much to win. And after running the deck a few times with Citadel inside it, I have always won if I can resolve a Citadel. It's becoming that good in my mind.
Cavalier of Gales does everything this deck wants to do. Draw cards, put more back on top, shuffle if the top is all dead draws, and scry 2! Oh and it doesn't die, it gets shuffled back in. It's also a decent cmc for damage from Twilight Prophet and Sorin, Grim Nemesis. Literally it's the whole deck in one card almost.
Finally Liliana Vess acts as a win con for her ultimate but more importantly (and more frequently) her -2 ability to find any card and put it on top of your library fits into the rest of the tutor themes and the strengths of the deck. Liliana plus Sorin or Citadel usually means you're going to take the game pretty quickly.