Glimpse the Unthinkable

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Ashiok, Dream Render

Spells and abilities your opponents control can't cause their controller to search their library.
−1: Target player mills four cards. Then exile each opponent's graveyard.

Dreadhorde Invasion

At the beginning of your upkeep, you lose 1 life and amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.

Memory Erosion

Whenever an opponent casts a spell, that player mills two cards.

Leyline of the Void

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield.
If a card would be put into an opponent's graveyard from anywhere, exile it instead.

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Skywise Teachings

Whenever you cast a noncreature spell, you may pay {1}{U}. If you do, create a 2/2 blue Djinn Monk creature token with flying.

Drawn from Dreams

Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in a random order.

Sphinx's Tutelage

Whenever you draw a card, target opponent mills two cards. If two nonland cards that share a color were milled this way, repeat this process.
{5}{U}: Draw a card, then discard a card.

Counterspell

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Countersquall

Counter target noncreature spell. Its controller loses 2 life.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Whispering Madness

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)