Prototype Portal

Imprint — When this artifact enters, you may exile an artifact card from your hand.
{X}, {T}: Create a token that's a copy of the exiled card. X is the mana value of that card.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Spellskite

{U/P}: Change a target of target spell or ability to this creature. ({U/P} can be paid with either {U} or 2 life.)

Tundra

Counterspell

Ancient Spring

This land enters tapped.
{T}: Add {U}.
{T}, Sacrifice this land: Add {W}{B}.

Underground Sea

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Urza, Lord High Artificer

When Urza enters, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."
Tap an untapped artifact you control: Add {U}.
{5}: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost.

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Memnite

Dromar's Cavern

When this land enters, sacrifice it unless you return a non-Lair land you control to its owner's hand.
{T}: Add {W}, {U}, or {B}.

Damnation

Destroy all creatures. They can't be regenerated.

Blue Sun's Zenith

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

Tome Scour

Myrsmith

Whenever you cast an artifact spell, you may pay {1}. If you do, create a 1/1 colorless Myr artifact creature token.