Mana Leak

Counter target spell unless its controller pays {3}.

Seat of the Synod

Viridian Longbow

Equipped creature has "{T}: This creature deals 1 damage to any target."
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Palace Sentinels

When this creature enters, you become the monarch.

Lone Missionary

When this creature enters, you gain 4 life.

Flayer Husk

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1.
Equip {2}

Bonesplitter

Thraben Inspector

When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Ancient Den

Azorius Chancery

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Trinket Mage

When this creature enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Guardian of the Guildpact

Plains

Swift Response

Mulldrifter

Flying
When this creature enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Dispeller's Capsule

{2}{W}, {T}, Sacrifice this artifact: Destroy target artifact or enchantment.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Relic of Progenitus

{T}: Target player exiles a card from their graveyard.
{1}, Exile this artifact: Exile all graveyards. Draw a card.

Fragmentize

Destroy target artifact or enchantment with mana value 4 or less.

Island

Journey to Nowhere

When this enchantment enters, exile target creature.
When this enchantment leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Sylvok Lifestaff

Equipped creature gets +1/+0.
Whenever equipped creature dies, you gain 3 life.
Equip {1}

Spell Pierce

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

Squadron Hawk

Flying
When this creature enters, you may search your library for up to three cards named Squadron Hawk, reveal them, put them into your hand, then shuffle.

Brainstorm

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

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Kor Skyfisher

Flying
When this creature enters, return a permanent you control to its owner's hand.