Composite Golem

Sacrifice Composite Golem: Add {W}{U}{B}{R}{G}.

Nim Deathmantle

Equipped creature gets +2/+2, has intimidate, and is a black Zombie. (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a nontoken creature is put into your graveyard from the battlefield, you may pay {4}. If you do, return that card to the battlefield and attach Nim Deathmantle to it.
Equip {4}

Island

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Treasure Mage

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

Turntimber Ranger

Whenever Turntimber Ranger or another Ally you control enters, you may create a 2/2 green Wolf creature token. If you do, put a +1/+1 counter on Turntimber Ranger.

Legacy Weapon

{W}{U}{B}{R}{G}: Exile target permanent.
If Legacy Weapon would be put into a graveyard from anywhere, reveal Legacy Weapon and shuffle it into its owner's library instead.

Forest

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Somberwald Sage

{T}: Add three mana of any one color. Spend this mana only to cast creature spells.

Artificial Evolution

Change the text of target spell or permanent by replacing all instances of one creature type with another. The new creature type can't be Wall. (This effect lasts indefinitely.)

Birds of Paradise

Mana Leak

Counter target spell unless its controller pays {3}.

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Ludevic's Abomination

Ludevic's Test Subject

Defender
{1}{U}: Put a hatchling counter on Ludevic's Test Subject. Then if there are five or more hatchling counters on it, remove all of them and transform it.

Ludevic's Test Subject // Ludevic's Abomination

Moonmist

Transform all Humans. Prevent all combat damage that would be dealt this turn by creatures other than Werewolves and Wolves. (Only double-faced cards can be transformed.)

Spellseeker

When Spellseeker enters, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Temple of Mystery

Temple of Mystery enters tapped.
When Temple of Mystery enters, scry 1.
{T}: Add {G} or {U}.