Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Iceberg

This enchantment enters with X ice counters on it.
{3}: Put an ice counter on this enchantment.
Remove an ice counter from this enchantment: Add {C}.

Icy Prison

When this enchantment enters, exile target creature.
At the beginning of your upkeep, sacrifice this enchantment unless any player pays {3}.
When this enchantment leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Illusionary Forces

Flying
Cumulative upkeep {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Illusionary Presence

Cumulative upkeep {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
At the beginning of your upkeep, choose a land type. This creature gains landwalk of the chosen type until end of turn. (It can't be blocked as long as defending player controls a land of that type.)

Illusionary Terrain

Cumulative upkeep {2} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
As this enchantment enters, choose two basic land types.
Basic lands of the first chosen type are the second chosen type.

Illusionary Wall

Defender, flying, first strike
Cumulative upkeep {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Illusions of Grandeur

Cumulative upkeep {2} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When this enchantment enters, you gain 20 life.
When this enchantment leaves the battlefield, you lose 20 life.

Blinking Spirit

{0}: Return this creature to its owner's hand.

Infuse

Untap target artifact, creature, or land.
Draw a card at the beginning of the next turn's upkeep.

Krovikan Sorcerer

{T}, Discard a nonblack card: Draw a card.
{T}, Discard a black card: Draw two cards, then discard one of them.

Magus of the Unseen

{1}{U}, {T}: Untap target artifact an opponent controls and gain control of it until end of turn. It gains haste until end of turn. When you lose control of the artifact, tap it.

Mesmeric Trance

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
{U}, Discard a card: Draw a card.

Mistfolk

{U}: Counter target spell that targets this creature.

Musician

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
{T}: Put a music counter on target creature. If it doesn't have "At the beginning of your upkeep, destroy this creature unless you pay {1} for each music counter on it," it gains that ability.

Mystic Might

Enchant land you control
Cumulative upkeep {1}{U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Enchanted land has "{T}: Target creature gets +2/+2 until end of turn."

Ice Age