Broken Ambitions

Counter target spell unless its controller pays {X}. Clash with an opponent. If you win, that spell's controller mills four cards. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Ponder

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

Plains

Aethertow

Put target attacking or blocking creature on top of its owner's library.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)

Counterbore

Counter target spell. Search its controller's graveyard, hand, and library for all cards with the same name as that spell and exile them. Then that player shuffles.

Godhead of Awe

Flying
Other creatures have base power and toughness 1/1.

Runed Halo

As Runed Halo enters, choose a card name.
You have protection from the chosen card name. (You can't be targeted, dealt damage, or enchanted by anything with that name.)

Dream Fracture

Counter target spell. Its controller draws a card.
Draw a card.

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Steel of the Godhead

Enchant creature
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)
As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.

Oblivion Ring

When Oblivion Ring enters, exile another target nonland permanent.
When Oblivion Ring leaves the battlefield, return the exiled card to the battlefield under its owner's control.