Lantern of Insight

Players play with the top card of their libraries revealed.
{T}, Sacrifice this artifact: Target player shuffles.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Circu, Dimir Lobotomist

Whenever you cast a blue spell, exile the top card of target player's library.
Whenever you cast a black spell, exile the top card of target player's library.
Your opponents can't cast spells with the same name as a card exiled with Circu.

Isochron Scepter

Imprint — When this artifact enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Dramatic Reversal

Untap all nonland permanents you control.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.