Thirst for Knowledge

Draw three cards. Then discard two cards unless you discard an artifact card.

Myr Battlesphere

When Myr Battlesphere enters the battlefield, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Omen of the Sea

Flash
When Omen of the Sea enters the battlefield, scry 2, then draw a card.
{2}{U}, Sacrifice Omen of the Sea: Scry 2.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Ugin, the Spirit Dragon

+2: Ugin, the Spirit Dragon deals 3 damage to any target.
−X: Exile each permanent with mana value X or less that's one or more colors.
−10: You gain 7 life, draw seven cards, then put up to seven permanent cards from your hand onto the battlefield.

Karn, Scion of Urza

+1: Reveal the top two cards of your library. An opponent chooses one of them. Put that card into your hand and exile the other with a silver counter on it.
−1: Put a card you own with a silver counter on it from exile into your hand.
−2: Create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."

Remand

Counter target spell. If that spell is countered this way, put it into its owner's hand instead of into that player's graveyard.
Draw a card.

Condescend

Counter target spell unless its controller pays {X}. Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Spreading Seas

Enchant land
When Spreading Seas enters the battlefield, draw a card.
Enchanted land is an Island.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Aether Gust

Choose target spell or permanent that's red or green. Its owner puts it on the top or bottom of their library.

Chalice of the Void

Chalice of the Void enters the battlefield with X charge counters on it.
Whenever a player casts a spell with mana value equal to the number of charge counters on Chalice of the Void, counter that spell.

Spatial Contortion

({C} represents colorless mana.)
Target creature gets +3/-3 until end of turn.

Thought-Knot Seer

({C} represents colorless mana.)
When Thought-Knot Seer enters the battlefield, target opponent reveals their hand. You choose a nonland card from it and exile that card.
When Thought-Knot Seer leaves the battlefield, target opponent draws a card.

Dismember

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

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Oblivion Stone

{4}, {T}: Put a fate counter on target permanent.
{5}, {T}, Sacrifice Oblivion Stone: Destroy each nonland permanent without a fate counter on it, then remove all fate counters from all permanents.

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Relic of Progenitus

{T}: Target player exiles a card from their graveyard.
{1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

Karn Liberated

+4: Target player exiles a card from their hand.
−3: Exile target permanent.
−14: Restart the game, leaving in exile all non-Aura permanent cards exiled with Karn Liberated. Then put those cards onto the battlefield under your control.

Repeal

Return target nonland permanent with mana value X to its owner's hand.
Draw a card.

Treasure Mage

When Treasure Mage enters the battlefield, you may search your library for an artifact card with mana value 6 or greater, reveal it, put it into your hand, then shuffle.

Island

Wurmcoil Engine

Deathtouch, lifelink
When Wurmcoil Engine dies, create a 3/3 colorless Phyrexian Wurm artifact creature token with deathtouch and a 3/3 colorless Phyrexian Wurm artifact creature token with lifelink.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Sundering Titan

When Sundering Titan enters or leaves the battlefield, choose a land of each basic land type, then destroy those lands.

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Crucible of Worlds

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Tolaria West

Tolaria West enters the battlefield tapped.
{T}: Add {U}.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with mana value 0, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Walking Ballista

Walking Ballista enters the battlefield with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.